QByteArray

The QByteArray class provides an array of bytes. More

Inheritance diagram of PySide2.QtCore.QByteArray

Synopsis

Functions

Static functions

Detailed Description

QByteArray can be used to store both raw bytes (including ‘\0’s) and traditional 8-bit ‘\0’-terminated strings. Using QByteArray is much more convenient than using const char * . Behind the scenes, it always ensures that the data is followed by a ‘\0’ terminator, and uses implicit sharing (copy-on-write) to reduce memory usage and avoid needless copying of data.

In addition to QByteArray , Qt also provides the QString class to store string data. For most purposes, QString is the class you want to use. It stores 16-bit Unicode characters, making it easy to store non-ASCII/non-Latin-1 characters in your application. Furthermore, QString is used throughout in the Qt API. The two main cases where QByteArray is appropriate are when you need to store raw binary data, and when memory conservation is critical (e.g., with Qt for Embedded Linux).

One way to initialize a QByteArray is simply to pass a const char * to its constructor. For example, the following code creates a byte array of size 5 containing the data “Hello”:

ba = QByteArray("Hello")

Although the size() is 5, the byte array also maintains an extra ‘\0’ character at the end so that if a function is used that asks for a pointer to the underlying data (e.g. a call to data() ), the data pointed to is guaranteed to be ‘\0’-terminated.

QByteArray makes a deep copy of the const char * data, so you can modify it later without experiencing side effects. (If for performance reasons you don’t want to take a deep copy of the character data, use fromRawData() instead.)

Another approach is to set the size of the array using resize() and to initialize the data byte per byte. QByteArray uses 0-based indexes, just like C++ arrays. To access the byte at a particular index position, you can use operator[](). On non-const byte arrays, operator[]() returns a reference to a byte that can be used on the left side of an assignment. For example:

ba = QByteArray()
ba.resize(5)
ba[0] = 'H'
ba[1] = 'e'
ba[2] = 'l'
ba[3] = 'l'
ba[4] = 'o'

For read-only access, an alternative syntax is to use at() :

for i in range(0, ba.size()):
    if ba.at(i) >= 'a' and ba.at(i) <= 'f':
        print "Found character in range [a-f]"

at() can be faster than operator[](), because it never causes a deep copy to occur.

To extract many bytes at a time, use left() , right() , or mid() .

A QByteArray can embed ‘\0’ bytes. The size() function always returns the size of the whole array, including embedded ‘\0’ bytes, but excluding the terminating ‘\0’ added by QByteArray . For example:

QByteArray ba1("ca\0r\0t");
ba1.size();                     // Returns 2.
ba1.constData();                // Returns "ca" with terminating \0.

QByteArray ba2("ca\0r\0t", 3);
ba2.size();                     // Returns 3.
ba2.constData();                // Returns "ca\0" with terminating \0.

QByteArray ba3("ca\0r\0t", 4);
ba3.size();                     // Returns 4.
ba3.constData();                // Returns "ca\0r" with terminating \0.

const char cart[] = {'c', 'a', '\0', 'r', '\0', 't'};
QByteArray ba4(QByteArray::fromRawData(cart, 6));
ba4.size();                     // Returns 6.
ba4.constData();                // Returns "ca\0r\0t" without terminating \0.

If you want to obtain the length of the data up to and excluding the first ‘\0’ character, call qstrlen() on the byte array.

After a call to resize() , newly allocated bytes have undefined values. To set all the bytes to a particular value, call fill() .

To obtain a pointer to the actual character data, call data() or constData() . These functions return a pointer to the beginning of the data. The pointer is guaranteed to remain valid until a non-const function is called on the QByteArray . It is also guaranteed that the data ends with a ‘\0’ byte unless the QByteArray was created from a raw data . This ‘\0’ byte is automatically provided by QByteArray and is not counted in size() .

QByteArray provides the following basic functions for modifying the byte data: append() , prepend() , insert() , replace() , and remove() . For example:

x = QByteArray("and")
x.prepend("rock ")         # x == "rock and"
x.append(" roll")          # x == "rock and roll"
x.replace(5, 3, "&")       # x == "rock & roll"

The replace() and remove() functions’ first two arguments are the position from which to start erasing and the number of bytes that should be erased.

When you append() data to a non-empty array, the array will be reallocated and the new data copied to it. You can avoid this behavior by calling reserve() , which preallocates a certain amount of memory. You can also call capacity() to find out how much memory QByteArray actually allocated. Data appended to an empty array is not copied.

A frequent requirement is to remove whitespace characters from a byte array (‘\n’, ‘\t’, ‘ ‘, etc.). If you want to remove whitespace from both ends of a QByteArray , use trimmed() . If you want to remove whitespace from both ends and replace multiple consecutive whitespaces with a single space character within the byte array, use simplified() .

If you want to find all occurrences of a particular character or substring in a QByteArray , use indexOf() or lastIndexOf() . The former searches forward starting from a given index position, the latter searches backward. Both return the index position of the character or substring if they find it; otherwise, they return -1. For example, here’s a typical loop that finds all occurrences of a particular substring:

ba = QByteArray("We must be <b>bold</b>, very <b>bold</b>")
j = 0
while (j = ba.indexOf("<b>", j)) != -1:
    print "Found <b> tag at index position %d" % j
    ++j

If you simply want to check whether a QByteArray contains a particular character or substring, use contains() . If you want to find out how many times a particular character or substring occurs in the byte array, use count() . If you want to replace all occurrences of a particular value with another, use one of the two-parameter replace() overloads.

QByteArray s can be compared using overloaded operators such as operator<(), operator<=(), operator==(), operator>=(), and so on. The comparison is based exclusively on the numeric values of the characters and is very fast, but is not what a human would expect. localeAwareCompare() is a better choice for sorting user-interface strings.

For historical reasons, QByteArray distinguishes between a null byte array and an empty byte array. A null byte array is a byte array that is initialized using QByteArray ‘s default constructor or by passing (const char *)0 to the constructor. An empty byte array is any byte array with size 0. A null byte array is always empty, but an empty byte array isn’t necessarily null:

QByteArray().isNull()          # returns true
QByteArray().isEmpty()         # returns true

QByteArray("").isNull()        # returns false
QByteArray("").isEmpty()       # returns true

QByteArray("abc").isNull()     # returns false
QByteArray("abc").isEmpty()    # returns false

All functions except isNull() treat null byte arrays the same as empty byte arrays. For example, data() returns a pointer to a ‘\0’ character for a null byte array (not a null pointer), and QByteArray() compares equal to QByteArray (“”). We recommend that you always use isEmpty() and avoid isNull() .

Notes on Locale

Number-String Conversions

Functions that perform conversions between numeric data types and strings are performed in the C locale, irrespective of the user’s locale settings. Use QString to perform locale-aware conversions between numbers and strings.

8-bit Character Comparisons

In QByteArray , the notion of uppercase and lowercase and of which character is greater than or less than another character is locale dependent. This affects functions that support a case insensitive option or that compare or lowercase or uppercase their arguments. Case insensitive operations and comparisons will be accurate if both strings contain only ASCII characters. (If $LC_CTYPE is set, most Unix systems do “the right thing”.) Functions that this affects include contains() , indexOf() , lastIndexOf() , operator<(), operator<=(), operator>(), operator>=(), isLower() , isUpper() , toLower() and toUpper() .

This issue does not apply to QString s since they represent characters using Unicode.

See also

QString QBitArray

class QByteArray

QByteArray(arg__1)

QByteArray(arg__1)

QByteArray(arg__1)

QByteArray(size, c)

param size

int

param arg__1

PyByteArray

param c

char

Constructs an empty byte array.

See also

isEmpty()

Constructs a byte array of size size with every byte set to character ch .

See also

fill()

PySide2.QtCore.QByteArray.Base64Option

This enum contains the options available for encoding and decoding Base64. Base64 is defined by RFC 4648 , with the following options:

Constant

Description

QByteArray.Base64Encoding

(default) The regular Base64 alphabet, called simply “base64”

QByteArray.Base64UrlEncoding

An alternate alphabet, called “base64url”, which replaces two characters in the alphabet to be more friendly to URLs.

QByteArray.KeepTrailingEquals

(default) Keeps the trailing padding equal signs at the end of the encoded data, so the data is always a size multiple of four.

QByteArray.OmitTrailingEquals

Omits adding the padding equal signs at the end of the encoded data.

fromBase64() ignores the and options and will not flag errors in case they are missing or if there are too many of them.

New in version 5.2.

PySide2.QtCore.QByteArray.__getitem__()
PySide2.QtCore.QByteArray.__len__()
PySide2.QtCore.QByteArray.__mgetitem__()
PySide2.QtCore.QByteArray.__msetitem__()
PySide2.QtCore.QByteArray.__reduce__()
Return type

PyObject

PySide2.QtCore.QByteArray.__repr__()
Return type

PyObject

PySide2.QtCore.QByteArray.__setitem__()
PySide2.QtCore.QByteArray.__str__()
Return type

PyObject

PySide2.QtCore.QByteArray.append(c)
Parameters

cchar

Return type

QByteArray

This is an overloaded function.

Appends the character ch to this byte array.

PySide2.QtCore.QByteArray.append(a)
Parameters

aQByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.append(count, c)
Parameters
  • countint

  • cchar

Return type

QByteArray

This is an overloaded function.

Appends count copies of character ch to this byte array and returns a reference to this byte array.

If count is negative or zero nothing is appended to the byte array.

PySide2.QtCore.QByteArray.at(i)
Parameters

iint

Return type

char

Returns the character at index position i in the byte array.

i must be a valid index position in the byte array (i.e., 0 <= i < size() ).

See also

operator[]()

PySide2.QtCore.QByteArray.back()
Return type

char

Returns the last character in the byte array. Same as at(size() - 1) .

This function is provided for STL compatibility.

Warning

Calling this function on an empty byte array constitutes undefined behavior.

See also

front() at() operator[]()

PySide2.QtCore.QByteArray.capacity()
Return type

int

Returns the maximum number of bytes that can be stored in the byte array without forcing a reallocation.

The sole purpose of this function is to provide a means of fine tuning QByteArray ‘s memory usage. In general, you will rarely ever need to call this function. If you want to know how many bytes are in the byte array, call size() .

See also

reserve() squeeze()

PySide2.QtCore.QByteArray.cbegin()
Return type

str

Returns a const STL-style iterator pointing to the first character in the byte-array.

See also

begin() cend()

PySide2.QtCore.QByteArray.cend()
Return type

str

Returns a const STL-style iterator pointing to the imaginary character after the last character in the list.

See also

cbegin() end()

PySide2.QtCore.QByteArray.chop(n)
Parameters

nint

Removes n bytes from the end of the byte array.

If n is greater than size() , the result is an empty byte array.

Example:

ba = QByteArray("STARTTLS\r\n")
ba.chop(2)                 # ba == "STARTTLS"
PySide2.QtCore.QByteArray.chopped(len)
Parameters

lenint

Return type

QByteArray

Returns a byte array that contains the leftmost size() - len bytes of this byte array.

Note

The behavior is undefined if len is negative or greater than size() .

PySide2.QtCore.QByteArray.clear()

Clears the contents of the byte array and makes it null.

See also

resize() isNull()

PySide2.QtCore.QByteArray.compare(a[, cs=Qt.CaseSensitive])
Parameters
Return type

int

PySide2.QtCore.QByteArray.compare(c[, cs=Qt.CaseSensitive])
Parameters
  • c – str

  • csCaseSensitivity

Return type

int

Returns an integer less than, equal to, or greater than zero depending on whether this QByteArray sorts before, at the same position, or after the string pointed to by c . The comparison is performed according to case sensitivity cs .

See also

operator==

PySide2.QtCore.QByteArray.contains(c)
Parameters

cchar

Return type

bool

This is an overloaded function.

Returns true if the byte array contains the character ch ; otherwise returns false .

PySide2.QtCore.QByteArray.contains(a)
Parameters

aQByteArray

Return type

bool

PySide2.QtCore.QByteArray.count()
Return type

int

This is an overloaded function.

Same as size() .

PySide2.QtCore.QByteArray.count(c)
Parameters

cchar

Return type

int

This is an overloaded function.

Returns the number of occurrences of character ch in the byte array.

PySide2.QtCore.QByteArray.count(a)
Parameters

aQByteArray

Return type

int

PySide2.QtCore.QByteArray.data()
Return type

str

This is an overloaded function.

PySide2.QtCore.QByteArray.endsWith(c)
Parameters

cchar

Return type

bool

This is an overloaded function.

Returns true if this byte array ends with character ch ; otherwise returns false .

PySide2.QtCore.QByteArray.endsWith(a)
Parameters

aQByteArray

Return type

bool

PySide2.QtCore.QByteArray.fill(c[, size=-1])
Parameters
  • cchar

  • sizeint

Return type

QByteArray

Sets every byte in the byte array to character ch . If size is different from -1 (the default), the byte array is resized to size size beforehand.

Example:

ba = QByteArray("Istambul")
ba.fill('o')
# ba == "oooooooo"

ba.fill('X', 2)
# ba == "XX"

See also

resize()

static PySide2.QtCore.QByteArray.fromBase64(base64)
Parameters

base64QByteArray

Return type

QByteArray

Returns a decoded copy of the Base64 array base64 . Input is not checked for validity; invalid characters in the input are skipped, enabling the decoding process to continue with subsequent characters.

For example:

text = QByteArray.fromBase64("UXQgaXMgZ3JlYXQh")
text.data()            # returns "Qt is great!"

The algorithm used to decode Base64-encoded data is defined in RFC 4648 .

See also

toBase64()

static PySide2.QtCore.QByteArray.fromBase64(base64, options)
Parameters
Return type

QByteArray

This is an overloaded function.

Returns a decoded copy of the Base64 array base64 , using the alphabet defined by options . Input is not checked for validity; invalid characters in the input are skipped, enabling the decoding process to continue with subsequent characters.

For example:

QByteArray::fromBase64("PHA+SGVsbG8/PC9wPg==", QByteArray::Base64Encoding); // returns "<p>Hello?</p>"
QByteArray::fromBase64("PHA-SGVsbG8_PC9wPg==", QByteArray::Base64UrlEncoding); // returns "<p>Hello?</p>"

The algorithm used to decode Base64-encoded data is defined in RFC 4648 .

See also

toBase64()

static PySide2.QtCore.QByteArray.fromHex(hexEncoded)
Parameters

hexEncodedQByteArray

Return type

QByteArray

Returns a decoded copy of the hex encoded array hexEncoded . Input is not checked for validity; invalid characters in the input are skipped, enabling the decoding process to continue with subsequent characters.

For example:

text = QByteArray.fromHex("517420697320677265617421")
text.data()            # returns "Qt is great!"

See also

toHex()

static PySide2.QtCore.QByteArray.fromPercentEncoding(pctEncoded[, percent='%'])
Parameters
Return type

QByteArray

Returns a decoded copy of the URI/URL-style percent-encoded input . The percent parameter allows you to replace the ‘%’ character for another (for instance, ‘_’ or ‘=’).

For example:

QByteArray text = QByteArray::fromPercentEncoding("Qt%20is%20great%33");
text.data();            // returns "Qt is great!"

Note

Given invalid input (such as a string containing the sequence “%G5”, which is not a valid hexadecimal number) the output will be invalid as well. As an example: the sequence “%G5” could be decoded to ‘W’.

static PySide2.QtCore.QByteArray.fromRawData(arg__1)
Parameters

arg__1 – str

Return type

QByteArray

Constructs a QByteArray that uses the first size bytes of the data array. The bytes are not copied. The QByteArray will contain the data pointer. The caller guarantees that data will not be deleted or modified as long as this QByteArray and any copies of it exist that have not been modified. In other words, because QByteArray is an implicitly shared class and the instance returned by this function contains the data pointer, the caller must not delete data or modify it directly as long as the returned QByteArray and any copies exist. However, QByteArray does not take ownership of data , so the QByteArray destructor will never delete the raw data , even when the last QByteArray referring to data is destroyed.

A subsequent attempt to modify the contents of the returned QByteArray or any copy made from it will cause it to create a deep copy of the data array before doing the modification. This ensures that the raw data array itself will never be modified by QByteArray .

Here is an example of how to read data using a QDataStream on raw data in memory without copying the raw data into a QByteArray :

mydata = '\x00\x00\x03\x84\x78\x9c\x3b\x76'\
         '\xec\x18\xc3\x31\x0a\xf1\xcc\x99'\
         ...
         '\x6d\x5b'

data = QByteArray.fromRawData(mydata)
in_ = QDataStream(data, QIODevice.ReadOnly)
...

Warning

A byte array created with is not ‘\0’-terminated, unless the raw data contains a 0 character at position size . While that does not matter for QDataStream or functions like indexOf() , passing the byte array to a function accepting a const char * expected to be ‘\0’-terminated will fail.

See also

setRawData() data() constData()

PySide2.QtCore.QByteArray.front()
Return type

char

Returns the first character in the byte array. Same as at(0) .

This function is provided for STL compatibility.

Warning

Calling this function on an empty byte array constitutes undefined behavior.

See also

back() at() operator[]()

PySide2.QtCore.QByteArray.indexOf(a[, from=0])
Parameters
Return type

int

PySide2.QtCore.QByteArray.insert(i, a)
Parameters
Return type

QByteArray

PySide2.QtCore.QByteArray.insert(i, count, c)
Parameters
  • iint

  • countint

  • cchar

Return type

QByteArray

This is an overloaded function.

Inserts count copies of character ch at index position i in the byte array.

If i is greater than size() , the array is first extended using resize() .

PySide2.QtCore.QByteArray.isEmpty()
Return type

bool

Returns true if the byte array has size 0; otherwise returns false .

Example:

QByteArray().isEmpty()         # returns true
QByteArray("").isEmpty()       # returns true
QByteArray("abc").isEmpty()    # returns false

See also

size()

PySide2.QtCore.QByteArray.isLower()
Return type

bool

Returns true if this byte array contains only lowercase letters, otherwise returns false . The byte array is interpreted as a Latin-1 encoded string.

See also

isUpper() toLower()

PySide2.QtCore.QByteArray.isNull()
Return type

bool

Returns true if this byte array is null; otherwise returns false .

Example:

QByteArray().isNull()          # returns true
QByteArray("").isNull()        # returns false
QByteArray("abc").isNull()     # returns false

Qt makes a distinction between null byte arrays and empty byte arrays for historical reasons. For most applications, what matters is whether or not a byte array contains any data, and this can be determined using isEmpty() .

See also

isEmpty()

PySide2.QtCore.QByteArray.isSharedWith(other)
Parameters

otherQByteArray

Return type

bool

PySide2.QtCore.QByteArray.isUpper()
Return type

bool

Returns true if this byte array contains only uppercase letters, otherwise returns false . The byte array is interpreted as a Latin-1 encoded string.

See also

isLower() toUpper()

PySide2.QtCore.QByteArray.lastIndexOf(a[, from=-1])
Parameters
Return type

int

PySide2.QtCore.QByteArray.left(len)
Parameters

lenint

Return type

QByteArray

Returns a byte array that contains the leftmost len bytes of this byte array.

The entire byte array is returned if len is greater than size() .

Example:

x = QByteArray("Pineapple")
y = x.left(4)
# y == "Pine"
PySide2.QtCore.QByteArray.leftJustified(width[, fill=' '[, truncate=false]])
Parameters
  • widthint

  • fillchar

  • truncatebool

Return type

QByteArray

Returns a byte array of size width that contains this byte array padded by the fill character.

If truncate is false and the size() of the byte array is more than width , then the returned byte array is a copy of this byte array.

If truncate is true and the size() of the byte array is more than width , then any bytes in a copy of the byte array after position width are removed, and the copy is returned.

Example:

x = QByteArray("apple")
y = x.leftJustified(8, '.')   # y == "apple..."

See also

rightJustified()

PySide2.QtCore.QByteArray.length()
Return type

int

Same as size() .

PySide2.QtCore.QByteArray.mid(index[, len=-1])
Parameters
  • indexint

  • lenint

Return type

QByteArray

Returns a byte array containing len bytes from this byte array, starting at position pos .

If len is -1 (the default), or pos + len >= size() , returns a byte array containing all bytes starting at position pos until the end of the byte array.

Example:

x = QByteArray("Five pineapples")
y = x.mid(5, 4)     # y == "pine"
z = x.mid(5)        # z == "pineapples"
static PySide2.QtCore.QByteArray.number(arg__1[, f='g'[, prec=6]])
Parameters
  • arg__1double

  • fchar

  • precint

Return type

QByteArray

This is an overloaded function.

Returns a byte array that contains the printed value of n , formatted in format f with precision prec .

Argument n is formatted according to the f format specified, which is g by default, and can be any of the following:

Format

Meaning

e

format as [-]9.9e[+|-]999

E

format as [-]9.9E[+|-]999

f

format as [-]9.9

g

use e or f format, whichever is the most concise

G

use E or f format, whichever is the most concise

With ‘e’, ‘E’, and ‘f’, prec is the number of digits after the decimal point. With ‘g’ and ‘G’, prec is the maximum number of significant digits (trailing zeroes are omitted).

ba = QByteArray.number(12.3456, 'E', 3)
# ba == 1.235E+01

Note

The format of the number is not localized; the default C locale is used irrespective of the user’s locale.

See also

toDouble()

static PySide2.QtCore.QByteArray.number(arg__1[, base=10])
Parameters
  • arg__1int

  • baseint

Return type

QByteArray

Returns a byte array containing the string equivalent of the number n to base base (10 by default). The base can be any value between 2 and 36.

Example:

n = 63;
QByteArray.number(n)               # returns "63"
QByteArray.number(n, 16)           # returns "3f"
QByteArray.number(n, 16).toUpper() # returns "3F"

Note

The format of the number is not localized; the default C locale is used irrespective of the user’s locale.

See also

setNum() toInt()

static PySide2.QtCore.QByteArray.number(arg__1[, base=10])
Parameters
  • arg__1qlonglong

  • baseint

Return type

QByteArray

This is an overloaded function.

See also

toLongLong()

PySide2.QtCore.QByteArray.__ne__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.__ne__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__ne__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__ne__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__add__(a2)
Parameters

a2QByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.__add__(a2)
Parameters

a2char

Return type

QByteArray

PySide2.QtCore.QByteArray.__add__(arg__1)
Parameters

arg__1PyBytes

PySide2.QtCore.QByteArray.__add__(arg__1)
Parameters

arg__1PyByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.__add__(arg__1)
Parameters

arg__1PyByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.__iadd__(arg__1)
Parameters

arg__1PyByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.__iadd__(c)
Parameters

cchar

Return type

QByteArray

This is an overloaded function.

Appends the character ch onto the end of this byte array and returns a reference to this byte array.

PySide2.QtCore.QByteArray.__iadd__(a)
Parameters

aQByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.__lt__(a2)
Parameters

a2 – str

Return type

bool

PySide2.QtCore.QByteArray.__lt__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__lt__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__lt__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.__lt__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__le__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__le__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__le__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__le__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.operator=(str)
Parameters

str – str

Return type

QByteArray

This is an overloaded function.

Assigns str to this byte array.

PySide2.QtCore.QByteArray.__eq__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__eq__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__eq__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__eq__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.__gt__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.__gt__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__gt__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__gt__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__ge__(arg__1)
Parameters

arg__1PyUnicode

PySide2.QtCore.QByteArray.__ge__(rhs)
Parameters

rhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.__ge__(a2)
Parameters

a2QByteArray

Return type

bool

PySide2.QtCore.QByteArray.__ge__(lhs)
Parameters

lhsQStringRef

Return type

bool

PySide2.QtCore.QByteArray.prepend(c)
Parameters

cchar

Return type

QByteArray

This is an overloaded function.

Prepends the character ch to this byte array.

PySide2.QtCore.QByteArray.prepend(a)
Parameters

aQByteArray

Return type

QByteArray

PySide2.QtCore.QByteArray.prepend(count, c)
Parameters
  • countint

  • cchar

Return type

QByteArray

This is an overloaded function.

Prepends count copies of character ch to this byte array.

PySide2.QtCore.QByteArray.remove(index, len)
Parameters
  • indexint

  • lenint

Return type

QByteArray

Removes len bytes from the array, starting at index position pos , and returns a reference to the array.

If pos is out of range, nothing happens. If pos is valid, but pos + len is larger than the size of the array, the array is truncated at position pos .

Example:

ba = QByteArray("Montreal")
ba.remove(1, 4)
# ba == "Meal"

See also

insert() replace()

PySide2.QtCore.QByteArray.repeated(times)
Parameters

timesint

Return type

QByteArray

Returns a copy of this byte array repeated the specified number of times .

If times is less than 1, an empty byte array is returned.

Example:

QByteArray ba("ab");
ba.repeated(4);             // returns "abababab"
PySide2.QtCore.QByteArray.replace(index, len, s)
Parameters
Return type

QByteArray

PySide2.QtCore.QByteArray.replace(before, after)
Parameters
Return type

QByteArray

PySide2.QtCore.QByteArray.replace(before, after)
Parameters
  • beforechar

  • afterchar

Return type

QByteArray

This is an overloaded function.

Replaces every occurrence of the character before with the character after .

PySide2.QtCore.QByteArray.replace(before, after)
Parameters
Return type

QByteArray

PySide2.QtCore.QByteArray.replace(before, after)
Parameters
Return type

QByteArray

PySide2.QtCore.QByteArray.reserve(size)
Parameters

sizeint

Attempts to allocate memory for at least size bytes. If you know in advance how large the byte array will be, you can call this function, and if you call resize() often you are likely to get better performance. If size is an underestimate, the worst that will happen is that the QByteArray will be a bit slower.

The sole purpose of this function is to provide a means of fine tuning QByteArray ‘s memory usage. In general, you will rarely ever need to call this function. If you want to change the size of the byte array, call resize() .

PySide2.QtCore.QByteArray.resize(size)
Parameters

sizeint

Sets the size of the byte array to size bytes.

If size is greater than the current size, the byte array is extended to make it size bytes with the extra bytes added to the end. The new bytes are uninitialized.

If size is less than the current size, bytes are removed from the end.

See also

size() truncate()

PySide2.QtCore.QByteArray.right(len)
Parameters

lenint

Return type

QByteArray

Returns a byte array that contains the rightmost len bytes of this byte array.

The entire byte array is returned if len is greater than size() .

Example:

x = QByteArray("Pineapple")
y = x.right(5)
# y == "apple"
PySide2.QtCore.QByteArray.rightJustified(width[, fill=' '[, truncate=false]])
Parameters
  • widthint

  • fillchar

  • truncatebool

Return type

QByteArray

Returns a byte array of size width that contains the fill character followed by this byte array.

If truncate is false and the size of the byte array is more than width , then the returned byte array is a copy of this byte array.

If truncate is true and the size of the byte array is more than width , then the resulting byte array is truncated at position width .

Example:

x = QByteArray("apple")
y = x.rightJustified(8, '.')    # y == "...apple"

See also

leftJustified()

PySide2.QtCore.QByteArray.setNum(arg__1[, base=10])
Parameters
  • arg__1qlonglong

  • baseint

Return type

QByteArray

This is an overloaded function.

See also

toLongLong()

PySide2.QtCore.QByteArray.setNum(arg__1[, base=10])
Parameters
  • arg__1int

  • baseint

Return type

QByteArray

Sets the byte array to the printed value of n in base base (10 by default) and returns a reference to the byte array. The base can be any value between 2 and 36. For bases other than 10, n is treated as an unsigned integer.

Example:

ba = QByteArray()
n = 63
ba.setNum(n)           # ba == "63"
ba.setNum(n, 16)       # ba == "3f"

Note

The format of the number is not localized; the default C locale is used irrespective of the user’s locale.

See also

number() toInt()

PySide2.QtCore.QByteArray.setNum(arg__1[, f='g'[, prec=6]])
Parameters
  • arg__1double

  • fchar

  • precint

Return type

QByteArray

This is an overloaded function.

Sets the byte array to the printed value of n , formatted in format f with precision prec , and returns a reference to the byte array.

The format f can be any of the following:

Format

Meaning

e

format as [-]9.9e[+|-]999

E

format as [-]9.9E[+|-]999

f

format as [-]9.9

g

use e or f format, whichever is the most concise

G

use E or f format, whichever is the most concise

With ‘e’, ‘E’, and ‘f’, prec is the number of digits after the decimal point. With ‘g’ and ‘G’, prec is the maximum number of significant digits (trailing zeroes are omitted).

Note

The format of the number is not localized; the default C locale is used irrespective of the user’s locale.

See also

toDouble()

PySide2.QtCore.QByteArray.setRawData(a, n)
Parameters
  • a – str

  • nuint

Return type

QByteArray

Resets the QByteArray to use the first size bytes of the data array. The bytes are not copied. The QByteArray will contain the data pointer. The caller guarantees that data will not be deleted or modified as long as this QByteArray and any copies of it exist that have not been modified.

This function can be used instead of fromRawData() to re-use existing QByteArray objects to save memory re-allocations.

See also

fromRawData() data() constData()

PySide2.QtCore.QByteArray.shrink_to_fit()

This function is provided for STL compatibility. It is equivalent to squeeze() .

PySide2.QtCore.QByteArray.simplified()
Return type

QByteArray

Returns a byte array that has whitespace removed from the start and the end, and which has each sequence of internal whitespace replaced with a single space.

Whitespace means any character for which the standard C++ isspace() function returns true in the C locale. This includes the ASCII isspace() function returns true in the C locale. This includes the ASCII characters ‘\t’, ‘\n’, ‘\v’, ‘\f’, ‘\r’, and ‘ ‘.

Example:

ba = QByteArray("  lots\t of\nwhitespace\r\n ")
ba = ba.simplified()
# ba == "lots of whitespace";

See also

trimmed()

PySide2.QtCore.QByteArray.size()
Return type

int

Returns the number of bytes in this byte array.

The last byte in the byte array is at position - 1. In addition, QByteArray ensures that the byte at position is always ‘\0’, so that you can use the return value of data() and constData() as arguments to functions that expect ‘\0’-terminated strings. If the QByteArray object was created from a raw data that didn’t include the trailing null-termination character then QByteArray doesn’t add it automaticall unless the deep copy is created.

Example:

ba = QByteArray("Hello")
n = ba.size()          # n == 5
ba.data()[0]           # returns 'H'
ba.data()[4]           # returns 'o'

See also

isEmpty() resize()

PySide2.QtCore.QByteArray.split(sep)
Parameters

sepchar

Return type

Splits the byte array into subarrays wherever sep occurs, and returns the list of those arrays. If sep does not match anywhere in the byte array, returns a single-element list containing this byte array.

PySide2.QtCore.QByteArray.squeeze()

Releases any memory not required to store the array’s data.

The sole purpose of this function is to provide a means of fine tuning QByteArray ‘s memory usage. In general, you will rarely ever need to call this function.

PySide2.QtCore.QByteArray.startsWith(c)
Parameters

cchar

Return type

bool

This is an overloaded function.

Returns true if this byte array starts with character ch ; otherwise returns false .

PySide2.QtCore.QByteArray.startsWith(a)
Parameters

aQByteArray

Return type

bool

PySide2.QtCore.QByteArray.swap(other)
Parameters

otherQByteArray

Swaps byte array other with this byte array. This operation is very fast and never fails.

PySide2.QtCore.QByteArray.toBase64()
Return type

QByteArray

Returns a copy of the byte array, encoded as Base64.

text = QByteArray("Qt is great!")
text.toBase64()        # returns "UXQgaXMgZ3JlYXQh"

The algorithm used to encode Base64-encoded data is defined in RFC 4648 .

See also

fromBase64()

PySide2.QtCore.QByteArray.toBase64(options)
Parameters

optionsBase64Options

Return type

QByteArray

This is an overloaded function.

Returns a copy of the byte array, encoded using the options options .

QByteArray text("<p>Hello?</p>");
text.toBase64(QByteArray::Base64Encoding | QByteArray::OmitTrailingEquals);      // returns "PHA+SGVsbG8/PC9wPg"
text.toBase64(QByteArray::Base64Encoding);                                       // returns "PHA+SGVsbG8/PC9wPg=="
text.toBase64(QByteArray::Base64UrlEncoding);                                    // returns "PHA-SGVsbG8_PC9wPg=="
text.toBase64(QByteArray::Base64UrlEncoding | QByteArray::OmitTrailingEquals);   // returns "PHA-SGVsbG8_PC9wPg"

The algorithm used to encode Base64-encoded data is defined in RFC 4648 .

See also

fromBase64()

PySide2.QtCore.QByteArray.toDouble()
Return type

double

Returns the byte array converted to a double value.

Returns an infinity if the conversion overflows or 0.0 if the conversion fails for other reasons (e.g. underflow).

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

string = QByteArray("1234.56")
(a, ok) = string.toDouble()   # a == 1234.56, ok == true

Warning

The QByteArray content may only contain valid numerical characters which includes the plus/minus sign, the character e used in scientific notation, and the decimal point. Including the unit or additional characters leads to a conversion error.

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

This function ignores leading and trailing whitespace.

See also

number()

PySide2.QtCore.QByteArray.toFloat()
Return type

float

Returns the byte array converted to a float value.

Returns an infinity if the conversion overflows or 0.0 if the conversion fails for other reasons (e.g. underflow).

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

QByteArray string("1234.56");
bool ok;
float a = string.toFloat(&ok);    // a == 1234.56, ok == true

string = "1234.56 Volt";
a = str.toFloat(&ok);              // a == 0, ok == false

Warning

The QByteArray content may only contain valid numerical characters which includes the plus/minus sign, the character e used in scientific notation, and the decimal point. Including the unit or additional characters leads to a conversion error.

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

This function ignores leading and trailing whitespace.

See also

number()

PySide2.QtCore.QByteArray.toHex()
Return type

QByteArray

Returns a hex encoded copy of the byte array. The hex encoding uses the numbers 0-9 and the letters a-f.

See also

fromHex()

PySide2.QtCore.QByteArray.toHex(separator)
Parameters

separatorchar

Return type

QByteArray

This is an overloaded function.

Returns a hex encoded copy of the byte array. The hex encoding uses the numbers 0-9 and the letters a-f.

If separator is not ‘\0’, the separator character is inserted between the hex bytes.

Example:

QByteArray macAddress = QByteArray::fromHex("123456abcdef");
macAddress.toHex(':'); // returns "12:34:56:ab:cd:ef"
macAddress.toHex(0);   // returns "123456abcdef"

See also

fromHex()

PySide2.QtCore.QByteArray.toInt([base=10])
Parameters

baseint

Return type

int

Returns the byte array converted to an int using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

string = QByteArray("FF")
(hex, ok) = string.toInt(16)   # hex == 255, ok == true
(dec, ok) = string.toInt(10)   # dec == 0, ok == false

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toLong([base=10])
Parameters

baseint

Return type

long

Returns the byte array converted to a long int using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

string = QByteArray("FF")
(hex, ok) = str.toLong(16);    # hex == 255, ok == true
(dec, ok) = str.toLong(10);    # dec == 0, ok == false

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toLongLong([base=10])
Parameters

baseint

Return type

qlonglong

Returns the byte array converted to a long long using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toLower()
Return type

QByteArray

Returns a lowercase copy of the byte array. The bytearray is interpreted as a Latin-1 encoded string.

Example:

x = QByteArray("Qt by THE QT COMPANY")
y = x.toLower()
# y == "qt by the qt company"

See also

isLower() toUpper() 8-bit Character Comparisons

PySide2.QtCore.QByteArray.toPercentEncoding([exclude=QByteArray()[, include=QByteArray()[, percent='%']]])
Parameters
Return type

QByteArray

Returns a URI/URL-style percent-encoded copy of this byte array. The percent parameter allows you to override the default ‘%’ character for another.

By default, this function will encode all characters that are not one of the following:

ALPHA (“a” to “z” and “A” to “Z”) / DIGIT (0 to 9) / “-” / “.” / “_” / “~”

To prevent characters from being encoded pass them to exclude . To force characters to be encoded pass them to include . The percent character is always encoded.

Example:

QByteArray text = "{a fishy string?}";
QByteArray ba = text.toPercentEncoding("{}", "s");
qDebug(ba.constData());
// prints "{a fi%73hy %73tring%3F}"

The hex encoding uses the numbers 0-9 and the uppercase letters A-F.

PySide2.QtCore.QByteArray.toShort([base=10])
Parameters

baseint

Return type

short

Returns the byte array converted to a short using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toUInt([base=10])
Parameters

baseint

Return type

uint

Returns the byte array converted to an unsigned int using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toULong([base=10])
Parameters

baseint

Return type

ulong

Returns the byte array converted to an unsigned long int using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toULongLong([base=10])
Parameters

baseint

Return type

qulonglong

Returns the byte array converted to an unsigned long long using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toUShort([base=10])
Parameters

baseint

Return type

ushort

Returns the byte array converted to an unsigned short using base base , which is 10 by default and must be between 2 and 36, or 0.

If base is 0, the base is determined automatically using the following rules: If the byte array begins with “0x”, it is assumed to be hexadecimal; if it begins with “0”, it is assumed to be octal; otherwise it is assumed to be decimal.

Returns 0 if the conversion fails.

If ok is not None , failure is reported by setting *``ok`` to false , and success by setting *``ok`` to true .

Note

The conversion of the number is performed in the default C locale, irrespective of the user’s locale.

See also

number()

PySide2.QtCore.QByteArray.toUpper()
Return type

QByteArray

Returns an uppercase copy of the byte array. The bytearray is interpreted as a Latin-1 encoded string.

Example:

x = QByteArray("Qt by THE QT COMPANY")
y = x.toUpper()
# y == "QT BY THE QT COMPANY"

See also

isUpper() toLower() 8-bit Character Comparisons

PySide2.QtCore.QByteArray.trimmed()
Return type

QByteArray

Returns a byte array that has whitespace removed from the start and the end.

Whitespace means any character for which the standard C++ isspace() function returns true in the C locale. This includes the ASCII characters ‘\t’, ‘\n’, ‘\v’, ‘\f’, ‘\r’, and ‘ ‘.

Example:

ba = QByteArray("  lots\t of\nwhitespace\r\n ");
ba = ba.trimmed();
# ba == "lots\t of\nwhitespace";

Unlike simplified() , leaves internal whitespace alone.

See also

simplified()

PySide2.QtCore.QByteArray.truncate(pos)
Parameters

posint

Truncates the byte array at index position pos .

If pos is beyond the end of the array, nothing happens.

Example:

ba = QByteArray("Stockholm")
ba.truncate(5)             # ba == "Stock"