Python regex not working as expected

Question

Why does the following python regex not generate @Summary\n?

import re
re.sub('$~ ','@','~ Summary\n')

Tim Pietzcker · Accepted Answer · 2013-11-29 09:34:16Z

3

The anchor $ means "the position at the end of the string".

You need to use a different anchor for "the position at the start of the string":

re.sub(r'^~ ','@','~ Summary\n')

answered Nov 29, 2013 at 9:28

Tim Pietzcker

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6 Comments

You sure you don't mean replace it with ^?

And maybe, say re.sub(r'\$~ ','@','$~ Summary\n') instead! (in order to get the expected result)

@user2357112 Looking at the input, it seems that you're right.

@devnull: And that is why I always teach my students to be skeptical of what authority figures say, including myself :)

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