django1/django/utils/text.py

270 lines
9.2 KiB
Python

import re
from django.conf import settings
from django.utils.encoding import force_unicode
from django.utils.functional import allow_lazy
from django.utils.translation import ugettext_lazy
from htmlentitydefs import name2codepoint
# Capitalizes the first letter of a string.
capfirst = lambda x: x and force_unicode(x)[0].upper() + force_unicode(x)[1:]
capfirst = allow_lazy(capfirst, unicode)
def wrap(text, width):
"""
A word-wrap function that preserves existing line breaks and most spaces in
the text. Expects that existing line breaks are posix newlines.
"""
text = force_unicode(text)
def _generator():
it = iter(text.split(' '))
word = it.next()
yield word
pos = len(word) - word.rfind('\n') - 1
for word in it:
if "\n" in word:
lines = word.split('\n')
else:
lines = (word,)
pos += len(lines[0]) + 1
if pos > width:
yield '\n'
pos = len(lines[-1])
else:
yield ' '
if len(lines) > 1:
pos = len(lines[-1])
yield word
return u''.join(_generator())
wrap = allow_lazy(wrap, unicode)
def truncate_words(s, num):
"Truncates a string after a certain number of words."
s = force_unicode(s)
length = int(num)
words = s.split()
if len(words) > length:
words = words[:length]
if not words[-1].endswith('...'):
words.append('...')
return u' '.join(words)
truncate_words = allow_lazy(truncate_words, unicode)
def truncate_html_words(s, num):
"""
Truncates html to a certain number of words (not counting tags and
comments). Closes opened tags if they were correctly closed in the given
html.
"""
s = force_unicode(s)
length = int(num)
if length <= 0:
return u''
html4_singlets = ('br', 'col', 'link', 'base', 'img', 'param', 'area', 'hr', 'input')
# Set up regular expressions
re_words = re.compile(r'&.*?;|<.*?>|(\w[\w-]*)', re.U)
re_tag = re.compile(r'<(/)?([^ ]+?)(?: (/)| .*?)?>')
# Count non-HTML words and keep note of open tags
pos = 0
ellipsis_pos = 0
words = 0
open_tags = []
while words <= length:
m = re_words.search(s, pos)
if not m:
# Checked through whole string
break
pos = m.end(0)
if m.group(1):
# It's an actual non-HTML word
words += 1
if words == length:
ellipsis_pos = pos
continue
# Check for tag
tag = re_tag.match(m.group(0))
if not tag or ellipsis_pos:
# Don't worry about non tags or tags after our truncate point
continue
closing_tag, tagname, self_closing = tag.groups()
tagname = tagname.lower() # Element names are always case-insensitive
if self_closing or tagname in html4_singlets:
pass
elif closing_tag:
# Check for match in open tags list
try:
i = open_tags.index(tagname)
except ValueError:
pass
else:
# SGML: An end tag closes, back to the matching start tag, all unclosed intervening start tags with omitted end tags
open_tags = open_tags[i+1:]
else:
# Add it to the start of the open tags list
open_tags.insert(0, tagname)
if words <= length:
# Don't try to close tags if we don't need to truncate
return s
out = s[:ellipsis_pos] + ' ...'
# Close any tags still open
for tag in open_tags:
out += '</%s>' % tag
# Return string
return out
truncate_html_words = allow_lazy(truncate_html_words, unicode)
def get_valid_filename(s):
"""
Returns the given string converted to a string that can be used for a clean
filename. Specifically, leading and trailing spaces are removed; other
spaces are converted to underscores; and anything that is not a unicode
alphanumeric, dash, underscore, or dot, is removed.
>>> get_valid_filename("john's portrait in 2004.jpg")
u'johns_portrait_in_2004.jpg'
"""
s = force_unicode(s).strip().replace(' ', '_')
return re.sub(r'(?u)[^-\w.]', '', s)
get_valid_filename = allow_lazy(get_valid_filename, unicode)
def get_text_list(list_, last_word=ugettext_lazy(u'or')):
"""
>>> get_text_list(['a', 'b', 'c', 'd'])
u'a, b, c or d'
>>> get_text_list(['a', 'b', 'c'], 'and')
u'a, b and c'
>>> get_text_list(['a', 'b'], 'and')
u'a and b'
>>> get_text_list(['a'])
u'a'
>>> get_text_list([])
u''
"""
if len(list_) == 0: return u''
if len(list_) == 1: return force_unicode(list_[0])
return u'%s %s %s' % (', '.join([force_unicode(i) for i in list_][:-1]), force_unicode(last_word), force_unicode(list_[-1]))
get_text_list = allow_lazy(get_text_list, unicode)
def normalize_newlines(text):
return force_unicode(re.sub(r'\r\n|\r|\n', '\n', text))
normalize_newlines = allow_lazy(normalize_newlines, unicode)
def recapitalize(text):
"Recapitalizes text, placing caps after end-of-sentence punctuation."
text = force_unicode(text).lower()
capsRE = re.compile(r'(?:^|(?<=[\.\?\!] ))([a-z])')
text = capsRE.sub(lambda x: x.group(1).upper(), text)
return text
recapitalize = allow_lazy(recapitalize)
def phone2numeric(phone):
"Converts a phone number with letters into its numeric equivalent."
letters = re.compile(r'[A-PR-Y]', re.I)
char2number = lambda m: {'a': '2', 'c': '2', 'b': '2', 'e': '3',
'd': '3', 'g': '4', 'f': '3', 'i': '4', 'h': '4', 'k': '5',
'j': '5', 'm': '6', 'l': '5', 'o': '6', 'n': '6', 'p': '7',
's': '7', 'r': '7', 'u': '8', 't': '8', 'w': '9', 'v': '8',
'y': '9', 'x': '9'}.get(m.group(0).lower())
return letters.sub(char2number, phone)
phone2numeric = allow_lazy(phone2numeric)
# From http://www.xhaus.com/alan/python/httpcomp.html#gzip
# Used with permission.
def compress_string(s):
import cStringIO, gzip
zbuf = cStringIO.StringIO()
zfile = gzip.GzipFile(mode='wb', compresslevel=6, fileobj=zbuf)
zfile.write(s)
zfile.close()
return zbuf.getvalue()
ustring_re = re.compile(u"([\u0080-\uffff])")
def javascript_quote(s, quote_double_quotes=False):
def fix(match):
return r"\u%04x" % ord(match.group(1))
if type(s) == str:
s = s.decode('utf-8')
elif type(s) != unicode:
raise TypeError, s
s = s.replace('\\', '\\\\')
s = s.replace('\r', '\\r')
s = s.replace('\n', '\\n')
s = s.replace('\t', '\\t')
s = s.replace("'", "\\'")
if quote_double_quotes:
s = s.replace('"', '&quot;')
return str(ustring_re.sub(fix, s))
javascript_quote = allow_lazy(javascript_quote, unicode)
# Expression to match some_token and some_token="with spaces" (and similarly
# for single-quoted strings).
smart_split_re = re.compile(r"""
([^\s"]*"(?:[^"\\]*(?:\\.[^"\\]*)*)"\S*|
[^\s']*'(?:[^'\\]*(?:\\.[^'\\]*)*)'\S*|
\S+)""", re.VERBOSE)
def smart_split(text):
r"""
Generator that splits a string by spaces, leaving quoted phrases together.
Supports both single and double quotes, and supports escaping quotes with
backslashes. In the output, strings will keep their initial and trailing
quote marks and escaped quotes will remain escaped (the results can then
be further processed with unescape_string_literal()).
>>> list(smart_split(r'This is "a person\'s" test.'))
[u'This', u'is', u'"a person\\\'s"', u'test.']
>>> list(smart_split(r"Another 'person\'s' test."))
[u'Another', u"'person\\'s'", u'test.']
>>> list(smart_split(r'A "\"funky\" style" test.'))
[u'A', u'"\\"funky\\" style"', u'test.']
"""
text = force_unicode(text)
for bit in smart_split_re.finditer(text):
yield bit.group(0)
smart_split = allow_lazy(smart_split, unicode)
def _replace_entity(match):
text = match.group(1)
if text[0] == u'#':
text = text[1:]
try:
if text[0] in u'xX':
c = int(text[1:], 16)
else:
c = int(text)
return unichr(c)
except ValueError:
return match.group(0)
else:
try:
return unichr(name2codepoint[text])
except (ValueError, KeyError):
return match.group(0)
_entity_re = re.compile(r"&(#?[xX]?(?:[0-9a-fA-F]+|\w{1,8}));")
def unescape_entities(text):
return _entity_re.sub(_replace_entity, text)
unescape_entities = allow_lazy(unescape_entities, unicode)
def unescape_string_literal(s):
r"""
Convert quoted string literals to unquoted strings with escaped quotes and
backslashes unquoted::
>>> unescape_string_literal('"abc"')
'abc'
>>> unescape_string_literal("'abc'")
'abc'
>>> unescape_string_literal('"a \"bc\""')
'a "bc"'
>>> unescape_string_literal("'\'ab\' c'")
"'ab' c"
"""
if s[0] not in "\"'" or s[-1] != s[0]:
raise ValueError("Not a string literal: %r" % s)
quote = s[0]
return s[1:-1].replace(r'\%s' % quote, quote).replace(r'\\', '\\')
unescape_string_literal = allow_lazy(unescape_string_literal)