String Replace only if whole word?
m.yanowitz at kearfott.com
Fri Nov 17 16:43:10 CET 2006
>Michael Yanowitz wrote:
>> I am hoping someone knows if there is an easier way to do this or
>> already implemented something that does this, rather than reinventing the
>> I have been using the string.replace(from_string, to_string,
>> to replace names in a file with their IP address.
>> For example, I have definitions file, that looks something like:
>> 10.1.3.4 LANDING_GEAR
>> 188.8.131.52 ALTIMETER_100
>> 172.18.50.138 SIB
>> 172.18.50.138 LAPTOP
>> 172.18.51.32 WIN2000
>> 127.0.0.1 LOCALHOST
>> and I have a text file (a Python script) that has these names in the
>> In most cases the string.replace() command works great. But there is one
>> instance which it fails:
>> Suppose I had in the file:
>> if (LAPTOP_IS_UP()):
>> It would replace the string with:
>> if ("172.18.50.138"_IS_UP()):
>> Is there any easy way to avoid this, only replace if a whole word
>> I probably need something which determines when a word ends, and I will
>> a word as containing only 'A'-'Z','a'-'z','0'-'9','_' . As long as the
>> contains more of the word digits after the match, don't replace?
>> Thanks in advance:
>> Michael Yanowitz
>You need regular expressions for this. Use the re module.
>from the docs:
>re.sub(pattern, repl, string[, count])
>Return the string obtained by replacing the leftmost non-overlapping
>occurrences of pattern in string by the replacement repl.
>Your pattern would be "[^A-Za-z0-9_]word[^A-Za-z0-9_]"
>[^xy] is approximately not in ('x', 'y')
This works great except for one thing:
The character after the replacement is deleted, so that if I have
send_data (LAPTOP, test_string)
it would replace it with:
send_data (10.1.3.4 test_string)
(ignoring that the 10.1.3.4 is not quoted). The comma is missing.
Thanks in advance:
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