CODEWITHSUNDEEP
pythonstringreplace
calccrypto
calccrypto

Reputation: 9001

specific searching in python?

Is there any way to search and replace certain strings, but also watch out for similar strings, and not replace those?

for example, if i have 

self.a
self.b
self.c
self.d
self.e
self.f
self.g

and i wanted

self.a
self.__b
self.c
self.__d
self.__e
self.f
self.g

and i want to add __ to some of the variables to make them private, but not others, how would i do it, short of changing each individually, or changing all of them and then undoing the ones i dont want? my program has a large number of variables and uses each of them very often, so i dont want to go through the code myself.

Upvotes: 0

Views: 177

Answers (4)

mklauber
mklauber

Reputation: 1144

Regular expressions are your friend here. They are a little intensive to the beginner, though. To accomplish the goal in the above example use the python command:

import re
pattern = r'(self\.)(b|d|e)\s'
result = re.sub(pattern, '\1__\2', source)

This takes every instance of a string starting with 'self.' followed by b, d, or e, and replaces it with a 'self.__' followed by the correct string.

Upvotes: 1

Andrew Clark
Andrew Clark

Reputation: 208705

In addition to creating another script to perform the replacement, you can probably do this in your editor. For example if you use Vim typing the following should do what you want:

:%s/self\.\(b\|d\|e\)/self.__\1/g

Upvotes: 1

user407896
user407896

Reputation: 940

Back up your script. Create a new script and import re, then re.sub() your original script. Run a unit test on the regex'd script to ensure functionality.

Upvotes: 1

Rafe Kettler
Rafe Kettler

Reputation: 76985

Regular expressions?

Python's re module has a function called re.sub which will replace everything matching a pattern with something else.

You can also use regular expressions from Perl, awk, sed, etc. depending on your preferences. Just search and replace based on whatever patterns you might want to match and change.

Upvotes: 3

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