如何用python删除字母[AZ]

Question

I want to delete letters from a string and save which is deleted in variable from these lines as below :

Input =

1.785K

10MEG

999.1V

Expected :

Value = 1.785
Units detected = K

Value = 10
Units detected = MEG

Value = 999.1
Units detected = V

I try this code but doens't work

list = ['1.785K','10MEG','999.1V']
for l in list:
  l.replace("[A-Z]", "")
  print("Value =" + l) 
  print("Units detected =" )

Answer 1

Because seems like your units are always at the end, you can avoid using regex and just use str.rstrip instead.

It removes a suffix of characters that can be provided as a string containing all chars to remove. the module string defines ascii_uppercase that contains all AZ chars.

as for getting the deleted chars, you can use the length of the stripped string to slice the original string and get exactly the removed chars

try this:

from string import ascii_uppercase

list = ['1.785K','10MEG','999.1V']
for l in list:
  after_strip = l.rstrip(ascii_uppercase)
  stripped_chars = l[len(after_strip):]
  print("Value = " + l) 
  print("Units detected = " + stripped_chars)

Answer 2

There you go:

I've solved this using regex

import re


input = '''1.785K

10MEG

999.1V
'''

for val,unit in re.findall('([0-9\.]+)([A-Za-z]+)',input):
    print('Value : ',val)
    print('Units : ',unit)
    print()

Output:

Value :  1.785
Units :  K

Value :  10
Units :  MEG

Value :  999.1
Units :  V

Regex link:

https://regex101.com/r/DZIaUM/1

Answer 3

You might use str translate method to get rid of unwanted characters

import string
t = str.maketrans('','',string.ascii_uppercase)
data = ["1.785K","10MEG","999.1V"]
for d in data:
    print(d.translate(t))

Output:

1.785
10
999.1

maketrans accepts 3 arguments, 2 first are empty in this case, because we need only to remove characters, not replace. However as you need these unit I suggest using re for that following way:

import re
data = ["1.785K","10MEG","999.1V"]
for d in data:
    print(re.findall(r'(.*?)([A-Z]+)',d))

Output:

[('1.785', 'K')]
[('10', 'MEG')]
[('999.1', 'V')]