Regex using Python to replace dot of floating numbers with "dot"

Question

I want to replace "." occurring in floating point numbers in my string with "dot" and vice versa.

Example:

t=' I am coder. I work in Google. I earn 98748.85'
Expected output: ' I am coder. I work in Google. I earn 98748dot85'
Then convert again: ' I am coder. I work in Google. I earn 98748.85'

My code:

 import re
 re.sub(r'\d+\.\d+',r"dot", t)
 output: ' I am coder. I work in Google. I earn dot'

score 3 · Accepted Answer · edited Jun 20 '20 at 09:12

3

You're replacing the entire match with "dot", not just the dot.

I know of two ways of solving this:

1. Positive lookaround assertions:

re.sub(r'(?<=\d)\.(?=\d)',r"dot", t)

In this solution, you're only matching the dot itself, but assert that there is a number before and behind it.

2. Catching the numbers and replacing with the capture groups and dot:

re.sub(r'(\d+)\.(\d+)',r"\1dot\2", t)

Here you match the entire float, but remember the part before and after the dot in capture groups. You then change the replacement string to be "the first capture group, then the string 'dot', then the second capture group".

edited Jun 20 '20 at 09:12

Community

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answered Feb 28 '18 at 09:45

L3viathan

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Thanks. It's working for me. And you mean to say for .85 it will not work? – DreamerP Feb 28 '18 at 10:00
Yes, that won't work with these suggestions. Do you also want 34. to work? – L3viathan Feb 28 '18 at 10:25
If the first number is optional, then you may as well remove it, i.e. `r'\.(?=\d)'` or `r'\.(\d+)'`. – L3viathan Feb 28 '18 at 10:53
I meant: it should work for all cases like 85.85, 85.0, 0.85, .85 so on.. the code should be generic. – DreamerP Feb 28 '18 at 11:04
Have you tried my suggestions? They would work for all your listed cases (but not for `34.`) – L3viathan Feb 28 '18 at 13:47

Regex using Python to replace dot of floating numbers with "dot"

1 Answers1

1. Positive lookaround assertions:

2. Catching the numbers and replacing with the capture groups and dot:

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