正则表达式在 Python 中替换选择特定的子字符串

Question

Here's what I want to happen:

input = "asdsad,200200-12964,0009,""TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589,037.17"" 0.00000000,1.000000"

output = "asdsad,200200-12964,0009,""TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589.037.17"" 0.00000000,1.000000"

How can I change the comma ( , ) to a dot ( . ) between ""...589,037.17..."" in Python using regex.

Extra: 589,037.17 => 589.037.17

I tried:

print(re.sub(r'(?<=\d),', '.', input))

But my output was:

output = "asdsad,200200-12964.0009,""TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589.037.17"" 0.00000000,1.000000"

Answer 1

First, don't call a variable input , because it overwrites the the built-in function input() . Also you repeated strings are just one string in Python.

i = 'asdsad,200200-12964,0009,TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589,037.17 0.00000000,1.000000'

To solve your specific case, you could match a the country code followed by 3 numbers in the first bit of the price before the comma. That works for this, but probably isn't generic enough for any country code and any price, as look-behinds must be of fixed width.

print(re.sub(r'(?<=USD \d{3}),', '.', i))

I would use a look-behind for the country code and space, then group the first bit of the number and replace it with a backreference.

print(re.sub(r'(?<=[A-Z]{3} )(\d+),', r'\1.', i))

Answer 2

import re

input = "asdsad,200200-12964,0009,""TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589,037.17"" 0.00000000,1.000000"
print(input)
print(re.sub(r'USD (\d+),(\d+)', r'USD \1.\2', input))

Output:

asdsad,200200-12964,0009,TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589,037.17 0.00000000,1.000000
asdsad,200200-12964,0009,TREASURY SETTLEMENT NON-COMPLIANCE ASSESSMENT FOR CPD2020-01-21 USD 589.037.17 0.00000000,1.000000

You can go through this Search and Replace andthis link for documenation on this.