9

how to replace multiple characters in a string?

please help to fix the script

I need to in the line "name" special characters have been replaced by the phrase "special char"

newName = replace(name, ['\', '/', ':', '*', '?', '"', '<', '>', '|'], 'special char')

but I get the message:

invalid syntax

Sergey
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  • have a look at [str.stranslate()](http://docs.python.org/3/library/stdtypes.html?highlight=translate#str.translate) – Fredrik Pihl Feb 18 '14 at 16:12
  • the invalid syntax error is coming from the first item in your list: '\'. Since it is an escape character you'd need to use '\\' – Cam Feb 18 '14 at 16:43

3 Answers3

15

You can use re.sub():

import re
newName = re.sub('[\\\\/:*?"<>|]', 'special char', name)
Mariusz Jamro
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11

You can use str.translate and a dictionary comprehension:

>>> name = ":1?2/3<4|5"
>>> bad = ['\\', '/', ':', '*', '?', '"', '<', '>', '|']
>>> newName = name.translate({ord(c):'special char' for c in bad})
>>> newName
'special char1special char2special char3special char4special char5'
>>>

If you use timeit.timeit, you will see that this method is generally faster than the others supplied:

>>> from timeit import timeit
>>> name = ":1?2/3<4|5"
>>> bad = ['\\', '/', ':', '*', '?', '"', '<', '>', '|']
>>>
>>> timeit("import re;re.sub('[\\/:*?\"<>|]', 'special char', name)", "from __main__ import name")
11.773986358601462
>>>
>>> timeit("for char in bad: name = name.replace(char, 'special char')", "from __main__ import name, bad")
9.943640323001944
>>>
>>> timeit("name.translate({ord(c):'special char' for c in bad})", "from __main__ import name, bad")
9.48467780122894
>>>
3

you could do something like:

>>> rep_chars = ['\\', '/', ':', '*', '?', '"', '<', '>', '|']
>>> name = "/:*?\"<>name"
>>> for char in rep_chars:
...     name = name.replace(char,'')
...
>>> name
'name'
Cam
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