how to extract part of string in python (the string length may vary)

Question

I'm having this string in my app which stores different percentage, I want to just extract the percentage value and convert it to int( ). My String looks something like this..

note: there will be one or more blank space(s) before the number.

result ='bFilesystem Size Used Avail Use% Mounted on\n/dev/sda4 30G 20G 8.4G 71% /\n'
percentage = getPercentage(result)   #This method should output 71 in this example
print("Percentage is: ", percentage)

Thank you in advance.

Well is it always like that? Then you could use a simple split function. — Anton vBR, Jun 10 '18 at 12:38
https://stackoverflow.com/questions/4289331/python-extract-numbers-from-a-string — Rajat, Jun 10 '18 at 12:49

Austin · Accepted Answer · 2018-06-10T12:54:37.817

4

You need a positive lookahead regex:

import re

result = 'demo percentage is   18%'
percentage = re.search(r'\d+(?=%)', result)        
print("Percentage is: ", percentage.group())

# Percentage is:  18

edited Jun 10 '18 at 12:54

answered Jun 10 '18 at 12:46

Austin

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Wasi Ahmad · Answer 2 · 2018-06-10T12:49:25.757

0

Using regular expression:

import re

inp_str = "demo percentage is   18%"
x = re.findall(r'\d+(?=%)', inp_str)
# x is a list of all numbers appeared in the input string
x = [int(i) for i in x]
print(x) # prints - [18]

edited Jun 10 '18 at 12:49

answered Jun 10 '18 at 12:43

Wasi Ahmad

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This doesn't work for `inp_str = "demo 11 percentage is 18%"`. – Austin Jun 10 '18 at 12:47
Yes, I know that my solution will not handle the above scenario but the question was not asked only to extract numbers that precede the `%` sign. Anyway, I have updated the answer. – Wasi Ahmad Jun 10 '18 at 12:51
result ='bFilesystem Size Used Avail Use% Mounted on\n/dev/sda4 30G 20G 8.4G 71% /\n' this is my string to be precise – Manoj Jahgirdar Jun 10 '18 at 12:54
@ManojJahgirdar please mention your requirements precisely from next time :) – Wasi Ahmad Jun 10 '18 at 12:55
@WasiAhmad yes sorry for the inconvenience. thank you.. :) – Manoj Jahgirdar Jun 10 '18 at 12:58

how to extract part of string in python (the string length may vary)

2 Answers2