1
2:mod:`netrc` --- netrc file processing
3======================================
4
5.. module:: netrc
6   :synopsis: Loading of .netrc files.
7
8.. moduleauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
9.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
10
11**Source code:** :source:`Lib/netrc.py`
12
13--------------
14
15The :class:`~netrc.netrc` class parses and encapsulates the netrc file format used by
16the Unix :program:`ftp` program and other FTP clients.
17
18
19.. class:: netrc([file])
20
21   A :class:`~netrc.netrc` instance or subclass instance encapsulates data from  a netrc
22   file.  The initialization argument, if present, specifies the file to parse.  If
23   no argument is given, the file :file:`.netrc` in the user's home directory --
24   as determined by :func:`os.path.expanduser` -- will be read.  Otherwise,
25   a :exc:`FileNotFoundError` exception will be raised.
26   Parse errors will raise :exc:`NetrcParseError` with diagnostic
27   information including the file name, line number, and terminating token.
28   If no argument is specified on a POSIX system, the presence of passwords in
29   the :file:`.netrc` file will raise a :exc:`NetrcParseError` if the file
30   ownership or permissions are insecure (owned by a user other than the user
31   running the process, or accessible for read or write by any other user).
32   This implements security behavior equivalent to that of ftp and other
33   programs that use :file:`.netrc`.
34
35   .. versionchanged:: 3.4 Added the POSIX permission check.
36
37   .. versionchanged:: 3.7
38      :func:`os.path.expanduser` is used to find the location of the
39      :file:`.netrc` file when *file* is not passed as argument.
40
41
42.. exception:: NetrcParseError
43
44   Exception raised by the :class:`~netrc.netrc` class when syntactical errors are
45   encountered in source text.  Instances of this exception provide three
46   interesting attributes:  :attr:`msg` is a textual explanation of the error,
47   :attr:`filename` is the name of the source file, and :attr:`lineno` gives the
48   line number on which the error was found.
49
50
51.. _netrc-objects:
52
53netrc Objects
54-------------
55
56A :class:`~netrc.netrc` instance has the following methods:
57
58
59.. method:: netrc.authenticators(host)
60
61   Return a 3-tuple ``(login, account, password)`` of authenticators for *host*.
62   If the netrc file did not contain an entry for the given host, return the tuple
63   associated with the 'default' entry.  If neither matching host nor default entry
64   is available, return ``None``.
65
66
67.. method:: netrc.__repr__()
68
69   Dump the class data as a string in the format of a netrc file. (This discards
70   comments and may reorder the entries.)
71
72Instances of :class:`~netrc.netrc` have public instance variables:
73
74
75.. attribute:: netrc.hosts
76
77   Dictionary mapping host names to ``(login, account, password)`` tuples.  The
78   'default' entry, if any, is represented as a pseudo-host by that name.
79
80
81.. attribute:: netrc.macros
82
83   Dictionary mapping macro names to string lists.
84
85.. note::
86
87   Passwords are limited to a subset of the ASCII character set.  All ASCII
88   punctuation is allowed in passwords, however, note that whitespace and
89   non-printable characters are not allowed in passwords.  This is a limitation
90   of the way the .netrc file is parsed and may be removed in the future.
91