QProcessEnvironment

The QProcessEnvironment class holds the environment variables that can be passed to a program. More…

New in version 4.6.

Synopsis

Functions

• def __eq__ (other)

• def __ne__ (other)

• def clear ()

• def contains (name)

• def insert (e)

• def insert (name, value)

• def isEmpty ()

• def keys ()

• def remove (name)

• def swap (other)

• def toStringList ()

• def value (name[, defaultValue=””])

Static functions

• def systemEnvironment ()

Detailed Description

A process’s environment is composed of a set of key=value pairs known as environment variables. The QProcessEnvironment class wraps that concept and allows easy manipulation of those variables. It’s meant to be used along with QProcess , to set the environment for child processes. It cannot be used to change the current process’s environment.

The environment of the calling process can be obtained using systemEnvironment() .

On Unix systems, the variable names are case-sensitive. Note that the Unix environment allows both variable names and contents to contain arbitrary binary data (except for the NUL character). QProcessEnvironment will preserve such variables, but does not support manipulating variables whose names or values cannot be encoded by the current locale settings (see codecForLocale ).

On Windows, the variable names are case-insensitive, but case-preserving. QProcessEnvironment behaves accordingly.

See also

QProcess systemEnvironment() setProcessEnvironment()

class PySide2.QtCore.QProcessEnvironment

PySide2.QtCore.QProcessEnvironment(other)

param other:

PySide2.QtCore.QProcessEnvironment

Creates a new QProcessEnvironment object. This constructor creates an empty environment. If set on a QProcess , this will cause the current environment variables to be removed.

Creates a QProcessEnvironment object that is a copy of other .

PySide2.QtCore.QProcessEnvironment.clear()

Removes all key=value pairs from this QProcessEnvironment object, making it empty.

See also

isEmpty() systemEnvironment()

PySide2.QtCore.QProcessEnvironment.contains(name)

Parameters:

name – str

Return type:

bool

Returns true if the environment variable of name name is found in this QProcessEnvironment object.

See also

insert() value()

PySide2.QtCore.QProcessEnvironment.insert(e)

Parameters:

e – PySide2.QtCore.QProcessEnvironment

This is an overloaded function.

Inserts the contents of e in this QProcessEnvironment object. Variables in this object that also exist in e will be overwritten.

PySide2.QtCore.QProcessEnvironment.insert(name, value)

Parameters:

• name – str

• value – str

Inserts the environment variable of name name and contents value into this QProcessEnvironment object. If that variable already existed, it is replaced by the new value.

On most systems, inserting a variable with no contents will have the same effect for applications as if the variable had not been set at all. However, to guarantee that there are no incompatibilities, to remove a variable, please use the remove() function.

See also

contains() remove() value()

PySide2.QtCore.QProcessEnvironment.isEmpty()

Return type:

bool

Returns true if this QProcessEnvironment object is empty: that is there are no key=value pairs set.

See also

clear() systemEnvironment() insert()

PySide2.QtCore.QProcessEnvironment.keys()

Return type:

list of strings

Returns a list containing all the variable names in this QProcessEnvironment object.

PySide2.QtCore.QProcessEnvironment.__ne__(other)

Parameters:

other – PySide2.QtCore.QProcessEnvironment

Return type:

bool

Returns true if this and the other QProcessEnvironment objects are different.

See also

operator==()

PySide2.QtCore.QProcessEnvironment.__eq__(other)

Parameters:

other – PySide2.QtCore.QProcessEnvironment

Return type:

bool

Returns true if this and the other QProcessEnvironment objects are equal.

Two QProcessEnvironment objects are considered equal if they have the same set of key=value pairs. The comparison of keys is done case-sensitive on platforms where the environment is case-sensitive.

See also

operator!=() contains()

PySide2.QtCore.QProcessEnvironment.remove(name)

Parameters:

name – str

Removes the environment variable identified by name from this QProcessEnvironment object. If that variable did not exist before, nothing happens.

See also

contains() insert() value()

PySide2.QtCore.QProcessEnvironment.swap(other)

Parameters:

other – PySide2.QtCore.QProcessEnvironment

Swaps this process environment instance with other . This function is very fast and never fails.

static PySide2.QtCore.QProcessEnvironment.systemEnvironment()

Return type:

PySide2.QtCore.QProcessEnvironment

The function returns the environment of the calling process.

It is returned as a QProcessEnvironment . This function does not cache the system environment. Therefore, it’s possible to obtain an updated version of the environment if low-level C library functions like setenv or putenv have been called.

However, note that repeated calls to this function will recreate the QProcessEnvironment object, which is a non-trivial operation.

See also

systemEnvironment()

PySide2.QtCore.QProcessEnvironment.toStringList()

Return type:

list of strings

Converts this QProcessEnvironment object into a list of strings, one for each environment variable that is set. The environment variable’s name and its value are separated by an equal character (‘=’).

The QStringList contents returned by this function are suitable for presentation. Use with the setEnvironment function is not recommended due to potential encoding problems under Unix, and worse performance.

See also

systemEnvironment() systemEnvironment() setProcessEnvironment()

PySide2.QtCore.QProcessEnvironment.value(name[, defaultValue=""])

Parameters:

• name – str

• defaultValue – str

Return type:

str

Searches this QProcessEnvironment object for a variable identified by name and returns its value. If the variable is not found in this object, then defaultValue is returned instead.

See also

contains() insert() remove()