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| """A collection of string constants. | |
| Public module variables: | |
| whitespace -- a string containing all ASCII whitespace | |
| ascii_lowercase -- a string containing all ASCII lowercase letters | |
| ascii_uppercase -- a string containing all ASCII uppercase letters | |
| ascii_letters -- a string containing all ASCII letters | |
| digits -- a string containing all ASCII decimal digits | |
| hexdigits -- a string containing all ASCII hexadecimal digits | |
| octdigits -- a string containing all ASCII octal digits | |
| punctuation -- a string containing all ASCII punctuation characters | |
| printable -- a string containing all ASCII characters considered printable | |
| """ | |
| __all__ = ["ascii_letters", "ascii_lowercase", "ascii_uppercase", "capwords", | |
| "digits", "hexdigits", "octdigits", "printable", "punctuation", | |
| "whitespace", "Formatter", "Template"] | |
| import _string | |
| # Some strings for ctype-style character classification | |
| whitespace = ' \t\n\r\v\f' | |
| ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz' | |
| ascii_uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' | |
| ascii_letters = ascii_lowercase + ascii_uppercase | |
| digits = '0123456789' | |
| hexdigits = digits + 'abcdef' + 'ABCDEF' | |
| octdigits = '01234567' | |
| punctuation = r"""!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~""" | |
| printable = digits + ascii_letters + punctuation + whitespace | |
| # Functions which aren't available as string methods. | |
| # Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def". | |
| def capwords(s, sep=None): | |
| """capwords(s [,sep]) -> string | |
| Split the argument into words using split, capitalize each | |
| word using capitalize, and join the capitalized words using | |
| join. If the optional second argument sep is absent or None, | |
| runs of whitespace characters are replaced by a single space | |
| and leading and trailing whitespace are removed, otherwise | |
| sep is used to split and join the words. | |
| """ | |
| return (sep or ' ').join(x.capitalize() for x in s.split(sep)) | |
| #################################################################### | |
| import re as _re | |
| from collections import ChainMap as _ChainMap | |
| _sentinel_dict = {} | |
| class _TemplateMetaclass(type): | |
| pattern = r""" | |
| %(delim)s(?: | |
| (?P<escaped>%(delim)s) | # Escape sequence of two delimiters | |
| (?P<named>%(id)s) | # delimiter and a Python identifier | |
| {(?P<braced>%(bid)s)} | # delimiter and a braced identifier | |
| (?P<invalid>) # Other ill-formed delimiter exprs | |
| ) | |
| """ | |
| def __init__(cls, name, bases, dct): | |
| super(_TemplateMetaclass, cls).__init__(name, bases, dct) | |
| if 'pattern' in dct: | |
| pattern = cls.pattern | |
| else: | |
| pattern = _TemplateMetaclass.pattern % { | |
| 'delim' : _re.escape(cls.delimiter), | |
| 'id' : cls.idpattern, | |
| 'bid' : cls.braceidpattern or cls.idpattern, | |
| } | |
| cls.pattern = _re.compile(pattern, cls.flags | _re.VERBOSE) | |
| class Template(metaclass=_TemplateMetaclass): | |
| """A string class for supporting $-substitutions.""" | |
| delimiter = '$' | |
| # r'[a-z]' matches to non-ASCII letters when used with IGNORECASE, but | |
| # without the ASCII flag. We can't add re.ASCII to flags because of | |
| # backward compatibility. So we use the ?a local flag and [a-z] pattern. | |
| # See https://bugs.python.org/issue31672 | |
| idpattern = r'(?a:[_a-z][_a-z0-9]*)' | |
| braceidpattern = None | |
| flags = _re.IGNORECASE | |
| def __init__(self, template): | |
| self.template = template | |
| # Search for $$, $identifier, ${identifier}, and any bare $'s | |
| def _invalid(self, mo): | |
| i = mo.start('invalid') | |
| lines = self.template[:i].splitlines(keepends=True) | |
| if not lines: | |
| colno = 1 | |
| lineno = 1 | |
| else: | |
| colno = i - len(''.join(lines[:-1])) | |
| lineno = len(lines) | |
| raise ValueError('Invalid placeholder in string: line %d, col %d' % | |
| (lineno, colno)) | |
| def substitute(self, mapping=_sentinel_dict, /, **kws): | |
| if mapping is _sentinel_dict: | |
| mapping = kws | |
| elif kws: | |
| mapping = _ChainMap(kws, mapping) | |
| # Helper function for .sub() | |
| def convert(mo): | |
| # Check the most common path first. | |
| named = mo.group('named') or mo.group('braced') | |
| if named is not None: | |
| return str(mapping[named]) | |
| if mo.group('escaped') is not None: | |
| return self.delimiter | |
| if mo.group('invalid') is not None: | |
| self._invalid(mo) | |
| raise ValueError('Unrecognized named group in pattern', | |
| self.pattern) | |
| return self.pattern.sub(convert, self.template) | |
| def safe_substitute(self, mapping=_sentinel_dict, /, **kws): | |
| if mapping is _sentinel_dict: | |
| mapping = kws | |
| elif kws: | |
| mapping = _ChainMap(kws, mapping) | |
| # Helper function for .sub() | |
| def convert(mo): | |
| named = mo.group('named') or mo.group('braced') | |
| if named is not None: | |
| try: | |
| return str(mapping[named]) | |
| except KeyError: | |
| return mo.group() | |
| if mo.group('escaped') is not None: | |
| return self.delimiter | |
| if mo.group('invalid') is not None: | |
| return mo.group() | |
| raise ValueError('Unrecognized named group in pattern', | |
| self.pattern) | |
| return self.pattern.sub(convert, self.template) | |
| ######################################################################## | |
| # the Formatter class | |
| # see PEP 3101 for details and purpose of this class | |
| # The hard parts are reused from the C implementation. They're exposed as "_" | |
| # prefixed methods of str. | |
| # The overall parser is implemented in _string.formatter_parser. | |
| # The field name parser is implemented in _string.formatter_field_name_split | |
| class Formatter: | |
| def format(self, format_string, /, *args, **kwargs): | |
| return self.vformat(format_string, args, kwargs) | |
| def vformat(self, format_string, args, kwargs): | |
| used_args = set() | |
| result, _ = self._vformat(format_string, args, kwargs, used_args, 2) | |
| self.check_unused_args(used_args, args, kwargs) | |
| return result | |
| def _vformat(self, format_string, args, kwargs, used_args, recursion_depth, | |
| auto_arg_index=0): | |
| if recursion_depth < 0: | |
| raise ValueError('Max string recursion exceeded') | |
| result = [] | |
| for literal_text, field_name, format_spec, conversion in \ | |
| self.parse(format_string): | |
| # output the literal text | |
| if literal_text: | |
| result.append(literal_text) | |
| # if there's a field, output it | |
| if field_name is not None: | |
| # this is some markup, find the object and do | |
| # the formatting | |
| # handle arg indexing when empty field_names are given. | |
| if field_name == '': | |
| if auto_arg_index is False: | |
| raise ValueError('cannot switch from manual field ' | |
| 'specification to automatic field ' | |
| 'numbering') | |
| field_name = str(auto_arg_index) | |
| auto_arg_index += 1 | |
| elif field_name.isdigit(): | |
| if auto_arg_index: | |
| raise ValueError('cannot switch from manual field ' | |
| 'specification to automatic field ' | |
| 'numbering') | |
| # disable auto arg incrementing, if it gets | |
| # used later on, then an exception will be raised | |
| auto_arg_index = False | |
| # given the field_name, find the object it references | |
| # and the argument it came from | |
| obj, arg_used = self.get_field(field_name, args, kwargs) | |
| used_args.add(arg_used) | |
| # do any conversion on the resulting object | |
| obj = self.convert_field(obj, conversion) | |
| # expand the format spec, if needed | |
| format_spec, auto_arg_index = self._vformat( | |
| format_spec, args, kwargs, | |
| used_args, recursion_depth-1, | |
| auto_arg_index=auto_arg_index) | |
| # format the object and append to the result | |
| result.append(self.format_field(obj, format_spec)) | |
| return ''.join(result), auto_arg_index | |
| def get_value(self, key, args, kwargs): | |
| if isinstance(key, int): | |
| return args[key] | |
| else: | |
| return kwargs[key] | |
| def check_unused_args(self, used_args, args, kwargs): | |
| pass | |
| def format_field(self, value, format_spec): | |
| return format(value, format_spec) | |
| def convert_field(self, value, conversion): | |
| # do any conversion on the resulting object | |
| if conversion is None: | |
| return value | |
| elif conversion == 's': | |
| return str(value) | |
| elif conversion == 'r': | |
| return repr(value) | |
| elif conversion == 'a': | |
| return ascii(value) | |
| raise ValueError("Unknown conversion specifier {0!s}".format(conversion)) | |
| # returns an iterable that contains tuples of the form: | |
| # (literal_text, field_name, format_spec, conversion) | |
| # literal_text can be zero length | |
| # field_name can be None, in which case there's no | |
| # object to format and output | |
| # if field_name is not None, it is looked up, formatted | |
| # with format_spec and conversion and then used | |
| def parse(self, format_string): | |
| return _string.formatter_parser(format_string) | |
| # given a field_name, find the object it references. | |
| # field_name: the field being looked up, e.g. "0.name" | |
| # or "lookup[3]" | |
| # used_args: a set of which args have been used | |
| # args, kwargs: as passed in to vformat | |
| def get_field(self, field_name, args, kwargs): | |
| first, rest = _string.formatter_field_name_split(field_name) | |
| obj = self.get_value(first, args, kwargs) | |
| # loop through the rest of the field_name, doing | |
| # getattr or getitem as needed | |
| for is_attr, i in rest: | |
| if is_attr: | |
| obj = getattr(obj, i) | |
| else: | |
| obj = obj[i] | |
| return obj, first |