Source code for boltons.strutils

# -*- coding: utf-8 -*-
"""So much practical programming involves string manipulation, which
Python readily accommodates. Still, there are dozens of basic and
common capabilities missing from the standard library, several of them
provided by ``strutils``.
"""

from __future__ import print_function

import re
import sys
import uuid
import zlib
import string
import unicodedata
import collections
from gzip import GzipFile

try:
    from cStringIO import cStringIO as StringIO
except ImportError:
    from io import BytesIO as StringIO

try:
    from collections.abc import Mapping
except ImportError:
    from collections import Mapping

try:
    unicode, str, bytes, basestring = unicode, str, str, basestring
    from HTMLParser import HTMLParser
    import htmlentitydefs
except NameError:  # basestring not defined in Python 3
    unicode, str, bytes, basestring = str, bytes, bytes, (str, bytes)
    unichr = chr
    from html.parser import HTMLParser
    from html import entities as htmlentitydefs


__all__ = ['camel2under', 'under2camel', 'slugify', 'split_punct_ws',
           'unit_len', 'ordinalize', 'cardinalize', 'pluralize', 'singularize',
           'asciify', 'is_ascii', 'is_uuid', 'html2text', 'strip_ansi',
           'bytes2human', 'find_hashtags', 'a10n', 'gzip_bytes', 'gunzip_bytes',
           'iter_splitlines', 'indent', 'escape_shell_args',
           'args2cmd', 'args2sh', 'parse_int_list', 'format_int_list']


_punct_ws_str = string.punctuation + string.whitespace
_punct_re = re.compile('[' + _punct_ws_str + ']+')
_camel2under_re = re.compile('((?<=[a-z0-9])[A-Z]|(?!^)[A-Z](?=[a-z]))')


[docs]def camel2under(camel_string): """Converts a camelcased string to underscores. Useful for turning a class name into a function name. >>> camel2under('BasicParseTest') 'basic_parse_test' """ return _camel2under_re.sub(r'_\1', camel_string).lower()
[docs]def under2camel(under_string): """Converts an underscored string to camelcased. Useful for turning a function name into a class name. >>> under2camel('complex_tokenizer') 'ComplexTokenizer' """ return ''.join(w.capitalize() or '_' for w in under_string.split('_'))
[docs]def slugify(text, delim='_', lower=True, ascii=False): """ A basic function that turns text full of scary characters (i.e., punctuation and whitespace), into a relatively safe lowercased string separated only by the delimiter specified by *delim*, which defaults to ``_``. The *ascii* convenience flag will :func:`asciify` the slug if you require ascii-only slugs. >>> slugify('First post! Hi!!!!~1 ') 'first_post_hi_1' >>> slugify("Kurt Gödel's pretty cool.", ascii=True) == \ b'kurt_goedel_s_pretty_cool' True """ ret = delim.join(split_punct_ws(text)) or delim if text else '' if ascii: ret = asciify(ret) if lower: ret = ret.lower() return ret
[docs]def split_punct_ws(text): """While :meth:`str.split` will split on whitespace, :func:`split_punct_ws` will split on punctuation and whitespace. This used internally by :func:`slugify`, above. >>> split_punct_ws('First post! Hi!!!!~1 ') ['First', 'post', 'Hi', '1'] """ return [w for w in _punct_re.split(text) if w]
[docs]def unit_len(sized_iterable, unit_noun='item'): # TODO: len_units()/unitize()? """Returns a plain-English description of an iterable's :func:`len()`, conditionally pluralized with :func:`cardinalize`, detailed below. >>> print(unit_len(range(10), 'number')) 10 numbers >>> print(unit_len('aeiou', 'vowel')) 5 vowels >>> print(unit_len([], 'worry')) No worries """ count = len(sized_iterable) units = cardinalize(unit_noun, count) if count: return u'%s %s' % (count, units) return u'No %s' % (units,)
_ORDINAL_MAP = {'1': 'st', '2': 'nd', '3': 'rd'} # 'th' is the default
[docs]def ordinalize(number, ext_only=False): """Turns *number* into its cardinal form, i.e., 1st, 2nd, 3rd, 4th, etc. If the last character isn't a digit, it returns the string value unchanged. Args: number (int or str): Number to be cardinalized. ext_only (bool): Whether to return only the suffix. Default ``False``. >>> print(ordinalize(1)) 1st >>> print(ordinalize(3694839230)) 3694839230th >>> print(ordinalize('hi')) hi >>> print(ordinalize(1515)) 1515th """ numstr, ext = unicode(number), '' if numstr and numstr[-1] in string.digits: try: # first check for teens if numstr[-2] == '1': ext = 'th' else: # all other cases ext = _ORDINAL_MAP.get(numstr[-1], 'th') except IndexError: # single digit numbers (will reach here based on [-2] above) ext = _ORDINAL_MAP.get(numstr[-1], 'th') if ext_only: return ext else: return numstr + ext
[docs]def cardinalize(unit_noun, count): """Conditionally pluralizes a singular word *unit_noun* if *count* is not one, preserving case when possible. >>> vowels = 'aeiou' >>> print(len(vowels), cardinalize('vowel', len(vowels))) 5 vowels >>> print(3, cardinalize('Wish', 3)) 3 Wishes """ if count == 1: return unit_noun return pluralize(unit_noun)
[docs]def singularize(word): """Semi-intelligently converts an English plural *word* to its singular form, preserving case pattern. >>> singularize('chances') 'chance' >>> singularize('Activities') 'Activity' >>> singularize('Glasses') 'Glass' >>> singularize('FEET') 'FOOT' """ orig_word, word = word, word.strip().lower() if not word or word in _IRR_S2P: return orig_word irr_singular = _IRR_P2S.get(word) if irr_singular: singular = irr_singular elif not word.endswith('s'): return orig_word elif len(word) == 2: singular = word[:-1] # or just return word? elif word.endswith('ies') and word[-4:-3] not in 'aeiou': singular = word[:-3] + 'y' elif word.endswith('es') and word[-3] == 's': singular = word[:-2] else: singular = word[:-1] return _match_case(orig_word, singular)
[docs]def pluralize(word): """Semi-intelligently converts an English *word* from singular form to plural, preserving case pattern. >>> pluralize('friend') 'friends' >>> pluralize('enemy') 'enemies' >>> pluralize('Sheep') 'Sheep' """ orig_word, word = word, word.strip().lower() if not word or word in _IRR_P2S: return orig_word irr_plural = _IRR_S2P.get(word) if irr_plural: plural = irr_plural elif word.endswith('y') and word[-2:-1] not in 'aeiou': plural = word[:-1] + 'ies' elif word[-1] == 's' or word.endswith('ch') or word.endswith('sh'): plural = word if word.endswith('es') else word + 'es' else: plural = word + 's' return _match_case(orig_word, plural)
def _match_case(master, disciple): if not master.strip(): return disciple if master.lower() == master: return disciple.lower() elif master.upper() == master: return disciple.upper() elif master.title() == master: return disciple.title() return disciple # Singular to plural map of irregular pluralizations _IRR_S2P = {'addendum': 'addenda', 'alga': 'algae', 'alumna': 'alumnae', 'alumnus': 'alumni', 'analysis': 'analyses', 'antenna': 'antennae', 'appendix': 'appendices', 'axis': 'axes', 'bacillus': 'bacilli', 'bacterium': 'bacteria', 'basis': 'bases', 'beau': 'beaux', 'bison': 'bison', 'bureau': 'bureaus', 'cactus': 'cacti', 'calf': 'calves', 'child': 'children', 'corps': 'corps', 'corpus': 'corpora', 'crisis': 'crises', 'criterion': 'criteria', 'curriculum': 'curricula', 'datum': 'data', 'deer': 'deer', 'diagnosis': 'diagnoses', 'die': 'dice', 'dwarf': 'dwarves', 'echo': 'echoes', 'elf': 'elves', 'ellipsis': 'ellipses', 'embargo': 'embargoes', 'emphasis': 'emphases', 'erratum': 'errata', 'fireman': 'firemen', 'fish': 'fish', 'focus': 'foci', 'foot': 'feet', 'formula': 'formulae', 'formula': 'formulas', 'fungus': 'fungi', 'genus': 'genera', 'goose': 'geese', 'half': 'halves', 'hero': 'heroes', 'hippopotamus': 'hippopotami', 'hoof': 'hooves', 'hypothesis': 'hypotheses', 'index': 'indices', 'knife': 'knives', 'leaf': 'leaves', 'life': 'lives', 'loaf': 'loaves', 'louse': 'lice', 'man': 'men', 'matrix': 'matrices', 'means': 'means', 'medium': 'media', 'memorandum': 'memoranda', 'millennium': 'milennia', 'moose': 'moose', 'mosquito': 'mosquitoes', 'mouse': 'mice', 'nebula': 'nebulae', 'neurosis': 'neuroses', 'nucleus': 'nuclei', 'oasis': 'oases', 'octopus': 'octopi', 'offspring': 'offspring', 'ovum': 'ova', 'ox': 'oxen', 'paralysis': 'paralyses', 'parenthesis': 'parentheses', 'person': 'people', 'phenomenon': 'phenomena', 'potato': 'potatoes', 'radius': 'radii', 'scarf': 'scarves', 'scissors': 'scissors', 'self': 'selves', 'series': 'series', 'sheep': 'sheep', 'shelf': 'shelves', 'species': 'species', 'stimulus': 'stimuli', 'stratum': 'strata', 'syllabus': 'syllabi', 'symposium': 'symposia', 'synopsis': 'synopses', 'synthesis': 'syntheses', 'tableau': 'tableaux', 'that': 'those', 'thesis': 'theses', 'thief': 'thieves', 'this': 'these', 'tomato': 'tomatoes', 'tooth': 'teeth', 'torpedo': 'torpedoes', 'vertebra': 'vertebrae', 'veto': 'vetoes', 'vita': 'vitae', 'watch': 'watches', 'wife': 'wives', 'wolf': 'wolves', 'woman': 'women'} # Reverse index of the above _IRR_P2S = dict([(v, k) for k, v in _IRR_S2P.items()]) HASHTAG_RE = re.compile(r"(?:^|\s)[##]{1}(\w+)", re.UNICODE)
[docs]def find_hashtags(string): """Finds and returns all hashtags in a string, with the hashmark removed. Supports full-width hashmarks for Asian languages and does not false-positive on URL anchors. >>> find_hashtags('#atag http://asite/#ananchor') ['atag'] ``find_hashtags`` also works with unicode hashtags. """ # the following works, doctest just struggles with it # >>> find_hashtags(u"can't get enough of that dignity chicken #肯德基 woo") # [u'\u80af\u5fb7\u57fa'] return HASHTAG_RE.findall(string)
[docs]def a10n(string): """That thing where "internationalization" becomes "i18n", what's it called? Abbreviation? Oh wait, no: ``a10n``. (It's actually a form of `numeronym`_.) >>> a10n('abbreviation') 'a10n' >>> a10n('internationalization') 'i18n' >>> a10n('') '' .. _numeronym: http://en.wikipedia.org/wiki/Numeronym """ if len(string) < 3: return string return '%s%s%s' % (string[0], len(string[1:-1]), string[-1])
ANSI_ESCAPE_BEGIN = '\x1b[' ANSI_TERMINATORS = ('H', 'f', 'A', 'B', 'C', 'D', 'R', 's', 'u', 'J', 'K', 'h', 'l', 'p', 'm')
[docs]def strip_ansi(text): """Strips ANSI escape codes from *text*. Useful for the occasional time when a log or redirected output accidentally captures console color codes and the like. >>> strip_ansi('\x1b[0m\x1b[1;36mart\x1b[46;34m\xdc') 'art' The test above is an excerpt from ANSI art on `sixteencolors.net`_. This function does not interpret or render ANSI art, but you can do so with `ansi2img`_ or `escapes.js`_. .. _sixteencolors.net: http://sixteencolors.net .. _ansi2img: http://www.bedroomlan.org/projects/ansi2img .. _escapes.js: https://github.com/atdt/escapes.js """ # TODO: move to cliutils.py nansi, keep, i, text_len = [], True, 0, len(text) while i < text_len: if not keep and text[i] in ANSI_TERMINATORS: keep = True elif keep: keep_end_i = text.find(ANSI_ESCAPE_BEGIN, i) if keep_end_i < 0: break else: nansi.append(text[i:keep_end_i]) i, keep = keep_end_i, False i += 1 if not nansi: return text return type(text)().join(nansi) # attempted unicode + str support
[docs]def asciify(text, ignore=False): """Converts a unicode or bytestring, *text*, into a bytestring with just ascii characters. Performs basic deaccenting for all you Europhiles out there. Also, a gentle reminder that this is a **utility**, primarily meant for slugification. Whenever possible, make your application work **with** unicode, not against it. Args: text (str or unicode): The string to be asciified. ignore (bool): Configures final encoding to ignore remaining unasciified unicode instead of replacing it. >>> asciify('Beyoncé') == b'Beyonce' True """ try: try: return text.encode('ascii') except UnicodeDecodeError: # this usually means you passed in a non-unicode string text = text.decode('utf-8') return text.encode('ascii') except UnicodeEncodeError: mode = 'replace' if ignore: mode = 'ignore' transd = unicodedata.normalize('NFKD', text.translate(DEACCENT_MAP)) ret = transd.encode('ascii', mode) return ret
[docs]def is_ascii(text): """Check if a unicode or bytestring, *text*, is composed of ascii characters only. Raises :exc:`ValueError` if argument is not text. Args: text (str or unicode): The string to be checked. >>> is_ascii('Beyoncé') False >>> is_ascii('Beyonce') True """ if isinstance(text, unicode): try: text.encode('ascii') except UnicodeEncodeError: return False elif isinstance(text, bytes): try: text.decode('ascii') except UnicodeDecodeError: return False else: raise ValueError('expected text or bytes, not %r' % type(text)) return True
class DeaccenterDict(dict): "A small caching dictionary for deaccenting." def __missing__(self, key): ch = self.get(key) if ch is not None: return ch try: de = unicodedata.decomposition(unichr(key)) p1, _, p2 = de.rpartition(' ') if int(p2, 16) == 0x308: ch = self.get(key) else: ch = int(p1, 16) except (IndexError, ValueError): ch = self.get(key, key) self[key] = ch return ch try: from collections import defaultdict except ImportError: # no defaultdict means that __missing__ isn't supported in # this version of python, so we define __getitem__ def __getitem__(self, key): try: return super(DeaccenterDict, self).__getitem__(key) except KeyError: return self.__missing__(key) else: del defaultdict # http://chmullig.com/2009/12/python-unicode-ascii-ifier/ # For something more complete, investigate the unidecode # or isounidecode packages, which are capable of performing # crude transliteration. _BASE_DEACCENT_MAP = { 0xc6: u"AE", # Æ LATIN CAPITAL LETTER AE 0xd0: u"D", # Ð LATIN CAPITAL LETTER ETH 0xd8: u"OE", # Ø LATIN CAPITAL LETTER O WITH STROKE 0xde: u"Th", # Þ LATIN CAPITAL LETTER THORN 0xc4: u'Ae', # Ä LATIN CAPITAL LETTER A WITH DIAERESIS 0xd6: u'Oe', # Ö LATIN CAPITAL LETTER O WITH DIAERESIS 0xdc: u'Ue', # Ü LATIN CAPITAL LETTER U WITH DIAERESIS 0xc0: u"A", # À LATIN CAPITAL LETTER A WITH GRAVE 0xc1: u"A", # Á LATIN CAPITAL LETTER A WITH ACUTE 0xc3: u"A", # Ã LATIN CAPITAL LETTER A WITH TILDE 0xc7: u"C", # Ç LATIN CAPITAL LETTER C WITH CEDILLA 0xc8: u"E", # È LATIN CAPITAL LETTER E WITH GRAVE 0xc9: u"E", # É LATIN CAPITAL LETTER E WITH ACUTE 0xca: u"E", # Ê LATIN CAPITAL LETTER E WITH CIRCUMFLEX 0xcc: u"I", # Ì LATIN CAPITAL LETTER I WITH GRAVE 0xcd: u"I", # Í LATIN CAPITAL LETTER I WITH ACUTE 0xd2: u"O", # Ò LATIN CAPITAL LETTER O WITH GRAVE 0xd3: u"O", # Ó LATIN CAPITAL LETTER O WITH ACUTE 0xd5: u"O", # Õ LATIN CAPITAL LETTER O WITH TILDE 0xd9: u"U", # Ù LATIN CAPITAL LETTER U WITH GRAVE 0xda: u"U", # Ú LATIN CAPITAL LETTER U WITH ACUTE 0xdf: u"ss", # ß LATIN SMALL LETTER SHARP S 0xe6: u"ae", # æ LATIN SMALL LETTER AE 0xf0: u"d", # ð LATIN SMALL LETTER ETH 0xf8: u"oe", # ø LATIN SMALL LETTER O WITH STROKE 0xfe: u"th", # þ LATIN SMALL LETTER THORN, 0xe4: u'ae', # ä LATIN SMALL LETTER A WITH DIAERESIS 0xf6: u'oe', # ö LATIN SMALL LETTER O WITH DIAERESIS 0xfc: u'ue', # ü LATIN SMALL LETTER U WITH DIAERESIS 0xe0: u"a", # à LATIN SMALL LETTER A WITH GRAVE 0xe1: u"a", # á LATIN SMALL LETTER A WITH ACUTE 0xe3: u"a", # ã LATIN SMALL LETTER A WITH TILDE 0xe7: u"c", # ç LATIN SMALL LETTER C WITH CEDILLA 0xe8: u"e", # è LATIN SMALL LETTER E WITH GRAVE 0xe9: u"e", # é LATIN SMALL LETTER E WITH ACUTE 0xea: u"e", # ê LATIN SMALL LETTER E WITH CIRCUMFLEX 0xec: u"i", # ì LATIN SMALL LETTER I WITH GRAVE 0xed: u"i", # í LATIN SMALL LETTER I WITH ACUTE 0xf2: u"o", # ò LATIN SMALL LETTER O WITH GRAVE 0xf3: u"o", # ó LATIN SMALL LETTER O WITH ACUTE 0xf5: u"o", # õ LATIN SMALL LETTER O WITH TILDE 0xf9: u"u", # ù LATIN SMALL LETTER U WITH GRAVE 0xfa: u"u", # ú LATIN SMALL LETTER U WITH ACUTE 0x2018: u"'", # ‘ LEFT SINGLE QUOTATION MARK 0x2019: u"'", # ’ RIGHT SINGLE QUOTATION MARK 0x201c: u'"', # “ LEFT DOUBLE QUOTATION MARK 0x201d: u'"', # ” RIGHT DOUBLE QUOTATION MARK } DEACCENT_MAP = DeaccenterDict(_BASE_DEACCENT_MAP) _SIZE_SYMBOLS = ('B', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y') _SIZE_BOUNDS = [(1024 ** i, sym) for i, sym in enumerate(_SIZE_SYMBOLS)] _SIZE_RANGES = list(zip(_SIZE_BOUNDS, _SIZE_BOUNDS[1:]))
[docs]def bytes2human(nbytes, ndigits=0): """Turns an integer value of *nbytes* into a human readable format. Set *ndigits* to control how many digits after the decimal point should be shown (default ``0``). >>> bytes2human(128991) '126K' >>> bytes2human(100001221) '95M' >>> bytes2human(0, 2) '0.00B' """ abs_bytes = abs(nbytes) for (size, symbol), (next_size, next_symbol) in _SIZE_RANGES: if abs_bytes <= next_size: break hnbytes = float(nbytes) / size return '{hnbytes:.{ndigits}f}{symbol}'.format(hnbytes=hnbytes, ndigits=ndigits, symbol=symbol)
class HTMLTextExtractor(HTMLParser): def __init__(self): self.reset() self.strict = False self.convert_charrefs = True self.result = [] def handle_data(self, d): self.result.append(d) def handle_charref(self, number): if number[0] == u'x' or number[0] == u'X': codepoint = int(number[1:], 16) else: codepoint = int(number) self.result.append(unichr(codepoint)) def handle_entityref(self, name): try: codepoint = htmlentitydefs.name2codepoint[name] except KeyError: self.result.append(u'&' + name + u';') else: self.result.append(unichr(codepoint)) def get_text(self): return u''.join(self.result)
[docs]def html2text(html): """Strips tags from HTML text, returning markup-free text. Also, does a best effort replacement of entities like "&nbsp;" >>> r = html2text(u'<a href="#">Test &amp;<em>(\u0394&#x03b7;&#956;&#x03CE;)</em></a>') >>> r == u'Test &(\u0394\u03b7\u03bc\u03ce)' True """ # based on answers to http://stackoverflow.com/questions/753052/ s = HTMLTextExtractor() s.feed(html) return s.get_text()
_EMPTY_GZIP_BYTES = b'\x1f\x8b\x08\x089\xf3\xb9U\x00\x03empty\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00' _NON_EMPTY_GZIP_BYTES = b'\x1f\x8b\x08\x08\xbc\xf7\xb9U\x00\x03not_empty\x00K\xaa,I-N\xcc\xc8\xafT\xe4\x02\x00\xf3nb\xbf\x0b\x00\x00\x00'
[docs]def gunzip_bytes(bytestring): """The :mod:`gzip` module is great if you have a file or file-like object, but what if you just have bytes. StringIO is one possibility, but it's often faster, easier, and simpler to just use this one-liner. Use this tried-and-true utility function to decompress gzip from bytes. >>> gunzip_bytes(_EMPTY_GZIP_BYTES) == b'' True >>> gunzip_bytes(_NON_EMPTY_GZIP_BYTES).rstrip() == b'bytesahoy!' True """ return zlib.decompress(bytestring, 16 + zlib.MAX_WBITS)
[docs]def gzip_bytes(bytestring, level=6): """Turn some bytes into some compressed bytes. >>> len(gzip_bytes(b'a' * 10000)) 46 Args: bytestring (bytes): Bytes to be compressed level (int): An integer, 1-9, controlling the speed/compression. 1 is fastest, least compressed, 9 is slowest, but most compressed. Note that all levels of gzip are pretty fast these days, though it's not really a competitor in compression, at any level. """ out = StringIO() f = GzipFile(fileobj=out, mode='wb', compresslevel=level) f.write(bytestring) f.close() return out.getvalue()
_line_ending_re = re.compile(r'(\r\n|\n|\x0b|\f|\r|\x85|\x2028|\x2029)', re.UNICODE)
[docs]def iter_splitlines(text): r"""Like :meth:`str.splitlines`, but returns an iterator of lines instead of a list. Also similar to :meth:`file.next`, as that also lazily reads and yields lines from a file. This function works with a variety of line endings, but as always, be careful when mixing line endings within a file. >>> list(iter_splitlines('\nhi\nbye\n')) ['', 'hi', 'bye', ''] >>> list(iter_splitlines('\r\nhi\rbye\r\n')) ['', 'hi', 'bye', ''] >>> list(iter_splitlines('')) [] """ prev_end, len_text = 0, len(text) # print('last: %r' % last_idx) # start, end = None, None for match in _line_ending_re.finditer(text): start, end = match.start(1), match.end(1) # print(start, end) if prev_end <= start: yield text[prev_end:start] if end == len_text: yield '' prev_end = end tail = text[prev_end:] if tail: yield tail return
[docs]def indent(text, margin, newline='\n', key=bool): """The missing counterpart to the built-in :func:`textwrap.dedent`. Args: text (str): The text to indent. margin (str): The string to prepend to each line. newline (str): The newline used to rejoin the lines (default: ``\\n``) key (callable): Called on each line to determine whether to indent it. Default: :class:`bool`, to ensure that empty lines do not get whitespace added. """ indented_lines = [(margin + line if key(line) else line) for line in iter_splitlines(text)] return newline.join(indented_lines)
[docs]def is_uuid(obj, version=4): """Check the argument is either a valid UUID object or string. Args: obj (object): The test target. Strings and UUID objects supported. version (int): The target UUID version, set to 0 to skip version check. >>> is_uuid('e682ccca-5a4c-4ef2-9711-73f9ad1e15ea') True >>> is_uuid('0221f0d9-d4b9-11e5-a478-10ddb1c2feb9') False >>> is_uuid('0221f0d9-d4b9-11e5-a478-10ddb1c2feb9', version=1) True """ if not isinstance(obj, uuid.UUID): try: obj = uuid.UUID(obj) except (TypeError, ValueError, AttributeError): return False if version and obj.version != int(version): return False return True
[docs]def escape_shell_args(args, sep=' ', style=None): """Returns an escaped version of each string in *args*, according to *style*. Args: args (list): A list of arguments to escape and join together sep (str): The separator used to join the escaped arguments. style (str): The style of escaping to use. Can be one of ``cmd`` or ``sh``, geared toward Windows and Linux/BSD/etc., respectively. If *style* is ``None``, then it is picked according to the system platform. See :func:`args2cmd` and :func:`args2sh` for details and example output for each style. """ if not style: style = 'cmd' if sys.platform == 'win32' else 'sh' if style == 'sh': return args2sh(args, sep=sep) elif style == 'cmd': return args2cmd(args, sep=sep) raise ValueError("style expected one of 'cmd' or 'sh', not %r" % style)
_find_sh_unsafe = re.compile(r'[^a-zA-Z0-9_@%+=:,./-]').search
[docs]def args2sh(args, sep=' '): """Return a shell-escaped string version of *args*, separated by *sep*, based on the rules of sh, bash, and other shells in the Linux/BSD/MacOS ecosystem. >>> print(args2sh(['aa', '[bb]', "cc'cc", 'dd"dd'])) aa '[bb]' 'cc'"'"'cc' 'dd"dd' As you can see, arguments with no special characters are not escaped, arguments with special characters are quoted with single quotes, and single quotes themselves are quoted with double quotes. Double quotes are handled like any other special character. Based on code from the :mod:`pipes`/:mod:`shlex` modules. Also note that :mod:`shlex` and :mod:`argparse` have functions to split and parse strings escaped in this manner. """ ret_list = [] for arg in args: if not arg: ret_list.append("''") continue if _find_sh_unsafe(arg) is None: ret_list.append(arg) continue # use single quotes, and put single quotes into double quotes # the string $'b is then quoted as '$'"'"'b' ret_list.append("'" + arg.replace("'", "'\"'\"'") + "'") return ' '.join(ret_list)
[docs]def args2cmd(args, sep=' '): r"""Return a shell-escaped string version of *args*, separated by *sep*, using the same rules as the Microsoft C runtime. >>> print(args2cmd(['aa', '[bb]', "cc'cc", 'dd"dd'])) aa [bb] cc'cc dd\"dd As you can see, escaping is through backslashing and not quoting, and double quotes are the only special character. See the comment in the code for more details. Based on internal code from the :mod:`subprocess` module. """ # technique description from subprocess below """ 1) Arguments are delimited by white space, which is either a space or a tab. 2) A string surrounded by double quotation marks is interpreted as a single argument, regardless of white space contained within. A quoted string can be embedded in an argument. 3) A double quotation mark preceded by a backslash is interpreted as a literal double quotation mark. 4) Backslashes are interpreted literally, unless they immediately precede a double quotation mark. 5) If backslashes immediately precede a double quotation mark, every pair of backslashes is interpreted as a literal backslash. If the number of backslashes is odd, the last backslash escapes the next double quotation mark as described in rule 3. See http://msdn.microsoft.com/en-us/library/17w5ykft.aspx or search http://msdn.microsoft.com for "Parsing C++ Command-Line Arguments" """ result = [] needquote = False for arg in args: bs_buf = [] # Add a space to separate this argument from the others if result: result.append(' ') needquote = (" " in arg) or ("\t" in arg) or not arg if needquote: result.append('"') for c in arg: if c == '\\': # Don't know if we need to double yet. bs_buf.append(c) elif c == '"': # Double backslashes. result.append('\\' * len(bs_buf)*2) bs_buf = [] result.append('\\"') else: # Normal char if bs_buf: result.extend(bs_buf) bs_buf = [] result.append(c) # Add remaining backslashes, if any. if bs_buf: result.extend(bs_buf) if needquote: result.extend(bs_buf) result.append('"') return ''.join(result)
[docs]def parse_int_list(range_string, delim=',', range_delim='-'): """Returns a sorted list of positive integers based on *range_string*. Reverse of :func:`format_int_list`. Args: range_string (str): String of comma separated positive integers or ranges (e.g. '1,2,4-6,8'). Typical of a custom page range string used in printer dialogs. delim (char): Defaults to ','. Separates integers and contiguous ranges of integers. range_delim (char): Defaults to '-'. Indicates a contiguous range of integers. >>> parse_int_list('1,3,5-8,10-11,15') [1, 3, 5, 6, 7, 8, 10, 11, 15] """ output = [] for x in range_string.strip().split(delim): # Range if range_delim in x: range_limits = list(map(int, x.split(range_delim))) output += list(range(min(range_limits), max(range_limits)+1)) # Empty String elif not x: continue # Integer else: output.append(int(x)) return sorted(output)
[docs]def format_int_list(int_list, delim=',', range_delim='-', delim_space=False): """Returns a sorted range string from a list of positive integers (*int_list*). Contiguous ranges of integers are collapsed to min and max values. Reverse of :func:`parse_int_list`. Args: int_list (list): List of positive integers to be converted into a range string (e.g. [1,2,4,5,6,8]). delim (char): Defaults to ','. Separates integers and contiguous ranges of integers. range_delim (char): Defaults to '-'. Indicates a contiguous range of integers. delim_space (bool): Defaults to ``False``. If ``True``, adds a space after all *delim* characters. >>> format_int_list([1,3,5,6,7,8,10,11,15]) '1,3,5-8,10-11,15' """ output = [] contig_range = collections.deque() for x in sorted(int_list): # Handle current (and first) value. if len(contig_range) < 1: contig_range.append(x) # Handle current value, given multiple previous values are contiguous. elif len(contig_range) > 1: delta = x - contig_range[-1] # Current value is contiguous. if delta == 1: contig_range.append(x) # Current value is non-contiguous. elif delta > 1: range_substr = '{0:d}{1}{2:d}'.format(min(contig_range), range_delim, max(contig_range)) output.append(range_substr) contig_range.clear() contig_range.append(x) # Current value repeated. else: continue # Handle current value, given no previous contiguous integers else: delta = x - contig_range[0] # Current value is contiguous. if delta == 1: contig_range.append(x) # Current value is non-contiguous. elif delta > 1: output.append('{0:d}'.format(contig_range.popleft())) contig_range.append(x) # Current value repeated. else: continue # Handle the last value. else: # Last value is non-contiguous. if len(contig_range) == 1: output.append('{0:d}'.format(contig_range.popleft())) contig_range.clear() # Last value is part of contiguous range. elif len(contig_range) > 1: range_substr = '{0:d}{1}{2:d}'.format(min(contig_range), range_delim, max(contig_range)) output.append(range_substr) contig_range.clear() if delim_space: output_str = (delim+' ').join(output) else: output_str = delim.join(output) return output_str
class MultiReplace(object): """ MultiReplace is a tool for doing multiple find/replace actions in one pass. Given a mapping of values to be replaced it allows for all of the matching values to be replaced in a single pass which can save a lot of performance on very large strings. In addition to simple replace, it also allows for replacing based on regular expressions. Keyword Arguments: :type regex: bool :param regex: Treat search keys as regular expressions [Default: False] :type flags: int :param flags: flags to pass to the regex engine during compile Dictionary Usage:: from lrmslib import stringutils s = stringutils.MultiReplace({ 'foo': 'zoo', 'cat': 'hat', 'bat': 'kraken' }) new = s.sub('The foo bar cat ate a bat') new == 'The zoo bar hat ate a kraken' Iterable Usage:: from lrmslib import stringutils s = stringutils.MultiReplace([ ('foo', 'zoo'), ('cat', 'hat'), ('bat', 'kraken)' ]) new = s.sub('The foo bar cat ate a bat') new == 'The zoo bar hat ate a kraken' The constructor can be passed a dictionary or other mapping as well as an iterable of tuples. If given an iterable, the substitution will be run in the order the replacement values are specified in the iterable. This is also true if it is given an OrderedDict. If given a dictionary then the order will be non-deterministic:: >>> 'foo bar baz'.replace('foo', 'baz').replace('baz', 'bar') 'bar bar bar' >>> m = MultiReplace({'foo': 'baz', 'baz': 'bar'}) >>> m.sub('foo bar baz') 'baz bar bar' This is because the order of replacement can matter if you're inserting something that might be replaced by a later substitution. Pay attention and if you need to rely on order then consider using a list of tuples instead of a dictionary. """ def __init__(self, sub_map, **kwargs): """Compile any regular expressions that have been passed.""" options = { 'regex': False, 'flags': 0, } options.update(kwargs) self.group_map = {} regex_values = [] if isinstance(sub_map, Mapping): sub_map = sub_map.items() for idx, vals in enumerate(sub_map): group_name = 'group{0}'.format(idx) if isinstance(vals[0], basestring): # If we're not treating input strings like a regex, escape it if not options['regex']: exp = re.escape(vals[0]) else: exp = vals[0] else: exp = vals[0].pattern regex_values.append('(?P<{0}>{1})'.format( group_name, exp )) self.group_map[group_name] = vals[1] self.combined_pattern = re.compile( '|'.join(regex_values), flags=options['flags'] ) def _get_value(self, match): """Given a match object find replacement value.""" group_dict = match.groupdict() key = [x for x in group_dict if group_dict[x]][0] return self.group_map[key] def sub(self, text): """ Run substitutions on the input text. Given an input string, run all substitutions given in the constructor. """ return self.combined_pattern.sub(self._get_value, text) def multi_replace(text, sub_map, **kwargs): """Shortcut function to invoke multi-replace in a single command.""" m = MultiReplace(sub_map, **kwargs) return m.sub(text) def unwrap_text(text, ending='\n\n'): r""" Unwrap text, the natural complement to :func:`textwrap.wrap`. >>> text = "Short \n lines \nwrapped\nsmall.\n\nAnother\nparagraph." >>> unwrap_text(text) 'Short lines wrapped small.\n\nAnother paragraph.' Args: text: A string to unwrap. ending (str): The string to join all unwrapped paragraphs by. Pass ``None`` to get the list. Defaults to '\n\n' for compatiblity with Markdown and RST. """ all_grafs = [] cur_graf = [] for line in text.splitlines(): line = line.strip() if line: cur_graf.append(line) else: all_grafs.append(' '.join(cur_graf)) cur_graf = [] if cur_graf: all_grafs.append(' '.join(cur_graf)) if ending is None: return all_grafs return ending.join(all_grafs)