This module provides access to operating system functionality that is standardized by the C Standard and the POSIX standard (a thinly disguised Unix interface).
Do not import this module directly. Instead, import the module
which provides a portable version of this interface. On Unix, the
module provides a superset of the
posix interface. On non-Unix operating
posix module is not available, but a subset is always
available through the
os interface. Once
os is imported, there is
no performance penalty in using it instead of
posix. In addition,
os provides some additional functionality, such as automatically calling
putenv() when an entry in
os.environ is changed.
Errors are reported as exceptions; the usual exceptions are given for type
errors, while errors reported by the system calls raise
Large File Support¶
Several operating systems (including AIX and Solaris) provide support for files that are larger than 2 GiB from a C programming model where int and long are 32-bit values. This is typically accomplished by defining the relevant size and offset types as 64-bit values. Such files are sometimes referred to as large files.
Large file support is enabled in Python when the size of an
larger than a long and the long long is at least as large
It may be necessary to configure and compile Python with certain compiler flags
to enable this mode. For example, with Solaris 2.6 and 2.7 you need to do
CFLAGS="`getconf LFS_CFLAGS`" OPT="-g -O2 $CFLAGS" \ ./configure
On large-file-capable Linux systems, this might work:
CFLAGS='-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64' OPT="-g -O2 $CFLAGS" \ ./configure
Notable Module Contents¶
A dictionary representing the string environment at the time the interpreter was started. Keys and values are bytes on Unix and str on Windows. For example,
environ['HOME']on Windows) is the pathname of your home directory, equivalent to
Modifying this dictionary does not affect the string environment passed on by
system(); if you need to change the environment, pass
execve()or add variable assignments and export statements to the command string for
Changed in version 3.2: On Unix, keys and values are bytes.