def iter_find(_str, to_find, n=0):
""" Finds all occurences of `to_find` in `_str`. Itering-ready. """
_str_len = len(_str)
to_find_len = len(to_find)
while n <= _str_len:
if _str[n:n+to_find_len] == to_find:
yield n
n += 1
def ireplace(text, old, new):
""" Replaces as occurences of `old` with the string pattern `new`.
The `new` variable has to be a string (additionally containing a
placeholder where the matches go (`%s`). """
assert(isinstance(text, str) and isinstance(old, str))
use_string_format = '%s' in new
old_len = len(old)
to_replace = []
for match in iter_find(text.lower(), old.lower()):
match = text[match:match+old_len]
if match not in to_replace:
if use_string_format:
to_replace.append((match, new % match))
else:
to_replace.append((match, new))
for rule in to_replace:
text = text.replace(*rule)
return text
