Python parsing numbers out of strings-CodePudding

I have a variety of strings that contain numbers:

examples:

>=5.0% or <=-6.25% 
>=6.25% or <=-7.813% 
<2.5% and >-3.125
>=2.5% or <=-3.125%
>=5.0% or <=-6.25% 
<5.0% or >-6.25%
<3.125 and >-3.906%

I am trying to figure out if there is a way that I can write a section of code that will give me both numbers, regardless of number of characters. Or if I am going to have to write code to parse every one differently. These are only some of the examples, I do not know exactly what all of my possible inputs are. And I do not seem to have a set character that I can partition on. I am looking for any suggestions or feedback.

CodePudding user response：

One possible approach to extract the numbers from the strings is to use regular expressions. The pattern for the numbers in the strings could be defined as follows:

pattern = r'[<>=] \s*-?\d .\d %?'

You could then use the re module in Python to find all matches in the strings:

import re

strings = [
">=5.0% or <=-6.25%",
">=6.25% or <=-7.813%",
"<2.5% and >-3.125",
">=2.5% or <=-3.125%",
">=5.0% or <=-6.25%",
"<5.0% or >-6.25%",
"<3.125 and >-3.906%",
]

for string in strings:
numbers = re.findall(pattern, string)
print(numbers)

This will return a list of strings that match the pattern in each input string, which you can then parse into numbers as needed.