Possible PEP Submission

MRAB python at mrabarnett.plus.com
Mon Dec 9 22:08:43 CET 2013


On 09/12/2013 20:36, Logan Collins wrote:
> Just checking whether 1) a PEP is the proper place for this and 2) what
> y'all think about it.
>
> I would like to propose a change to the the 're' standard library to
> support iterables.
>
> So, something like the following would work:
>
> import re
> text = """hello user
> hello user
> hello user"""
>
> users = ["Bob", "Alice", "Jeffery"]
>
> newtext = re.sub("user", users, text)
>
> # newtext = "hello Bob\nhello Alice\nhello Jeffery"
>
> There are a few corner cases I'm not sure what would be the best
> behavior. Nor am I entirely certain this should be modified
> functionality or just... a new function. What do y'all think?
>
What's your use-case? How often would someone want to do this?

Here's a way of doing it without adding to the re module:


import re

text = """hello user
hello user
hello user"""

class Replacement:
     def __init__(self, users):
         self.users = users
         self.index = -1

     def __call__(self, m):
         self.index += 1
         return self.users[self.index]

users = ["Bob", "Alice", "Jeffery"]

newtext = re.sub("user", Replacement(users), text)

# newtext = "hello Bob\nhello Alice\nhello Jeffery"
print(newtext)


The search string is a simple literal, so another way is:


from itertools import chain

text = """hello user
hello user
hello user"""

users = ["Bob", "Alice", "Jeffery"]

# newtext = "hello Bob\nhello Alice\nhello Jeffery"
newtext = "".join(chain(*zip(text.split("user", len(users)), users)))
print(newtext)




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