On Saturday, February 9, 2013 5:04:18 AM UTC-6, Joshua Robinson wrote:
> Hi Monte-Pythons,
>
> x = "this is a simple : text: that has colon"
> s = x.replace(string.punctuation, ""); OR
> s = x.replace(string.punctuation, "");
> print x # 'this is a simple : text: that has colon'
>
> # The colon is still in the text !!!!
>
> Is this a bug or am I doing something wrong ?
Not a bug, you are just expecting Python to read your mind. In actuality what
you are doing is asking the method "string.replace()" to replace the 32 char
string:
'!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~'
with the null string:
""
...what you INTENDED to do was have Python find every occurrence the each char
in the string you passed and replace them with the null string. You are
assuming the replace method handles sequences in the manner you are projecting.
Sorry, but string#replace does not work that way. Whether or not it should is
up for debate[1].
However, you can create a loop and pass the arguments "one-by-one" into the
method:
py> s = "a:b :c: d"
py> for char in string.punctuation:
s = s.replace(char, "")
py> s
'ab c d'
But this seems really wasteful if all you want is to remove colons. Are you
just removing the colons or truly wanting to remove ALL punctuation from the
string?
============================================================
REFERENCES:
============================================================
[1]: Should string.replace handle list, tuple and dict arguments in addition to
strings?
py> string.replace(('a', 'b', 'c'), 'abcdefgabc')
'defg'
py> string.replace(['a', 'b', 'c'], 'abcdefgabc')
'defg'
py> string.replace({'a':'A', 'b':'2', 'c':'C'}, 'abcdefgabc')
'A2CdefgA2C'
This would be a more consistent approach to me. Handling only string arguments
is woefully inadequate. Why would you have a programmer write a loop for this
every time?
@pydev&GvR
What is the justification for not processing (at the minimum) multiple
arguments? Do you think strings will most often only need one modification?
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