diff options
Diffstat (limited to 'cmd2/utils.py')
-rw-r--r-- | cmd2/utils.py | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/cmd2/utils.py b/cmd2/utils.py index 33215dc0..a975c6b8 100644 --- a/cmd2/utils.py +++ b/cmd2/utils.py @@ -2,8 +2,10 @@ # coding=utf-8 """Shared utility functions""" +import collections from . import constants + def strip_ansi(text: str) -> str: """Strip ANSI escape codes from a string. @@ -11,3 +13,46 @@ def strip_ansi(text: str) -> str: :return: the same string with any ANSI escape codes removed """ return constants.ANSI_ESCAPE_RE.sub('', text) + + +def strip_quotes(arg: str) -> str: + """ Strip outer quotes from a string. + + Applies to both single and double quotes. + + :param arg: string to strip outer quotes from + :return: same string with potentially outer quotes stripped + """ + if len(arg) > 1 and arg[0] == arg[-1] and arg[0] in constants.QUOTES: + arg = arg[1:-1] + return arg + + +def namedtuple_with_defaults(typename, field_names, default_values=()): + """ + Convenience function for defining a namedtuple with default values + + From: https://stackoverflow.com/questions/11351032/namedtuple-and-default-values-for-optional-keyword-arguments + + Examples: + >>> Node = namedtuple_with_defaults('Node', 'val left right') + >>> Node() + Node(val=None, left=None, right=None) + >>> Node = namedtuple_with_defaults('Node', 'val left right', [1, 2, 3]) + >>> Node() + Node(val=1, left=2, right=3) + >>> Node = namedtuple_with_defaults('Node', 'val left right', {'right':7}) + >>> Node() + Node(val=None, left=None, right=7) + >>> Node(4) + Node(val=4, left=None, right=7) + """ + T = collections.namedtuple(typename, field_names) + T.__new__.__defaults__ = (None,) * len(T._fields) + if isinstance(default_values, collections.Mapping): + prototype = T(**default_values) + else: + prototype = T(*default_values) + T.__new__.__defaults__ = tuple(prototype) + return T + |