Extracting floating point numbers in a string using regex

Question

I have the following list of strings

List = ['A = -25.47 dBm' , 'B = -47.35 dBm' , 'A = -26.54 dBm' , 'B = -32.35 dBm', 'A = 27.95 dBm' , 'B = -64.11 dBm' , 'A = -45.11 dBm' , 'B = -18.67 dBm']

I want to extract the values of A make a list of that, values of B and make a list of that

I have tried the following

#First I joined the data into a string
S = ' '.join(List)
re.findall(r"A =  ([-+]?\d*\.\d+|\d+) dBm" , S)

which doesn't seem to work

Expected Result

A_list = [-25.47,-26.54, 27.95,-45.11] 
B_list = [-47.35,-32.35,-64.11,-18.67]

Your regex has two spaces after = but the input has only one space after =. — Socowi
– Socowi, Commented Jul 29, 2019 at 21:55

Ajax1234 · Accepted Answer · 2019-07-29 21:54:15Z

1

You can use re and collections.defaultdict:

import re, collections
l = ['A = -25.47 dBm' , 'B = -47.35 dBm' , 'A = -26.54 dBm' , 'B = -32.35 dBm', 'A = 27.95 dBm' , 'B = -64.11 dBm' , 'A = -45.11 dBm' , 'B = -18.67 dBm']
d = collections.defaultdict(list)
for i in l:
  a, b = re.findall('^\w+|[\-\d\.]+', i)
  d[a].append(float(b))

A_list, B_list = d['A'], d['B']

Output:

[-25.47, -26.54, 27.95, -45.11]
[-47.35, -32.35, -64.11, -18.67]

answered Jul 29, 2019 at 21:54

Ajax1234

71.7k9 gold badges67 silver badges110 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

dd24 Over a year ago

isn't there a way to do in this format re.findall(r"A = ([-+]?\d*\.\d+|\d+) dBm" , S)

Ajax1234 Over a year ago

@dd24 That will work to extract the float value, but you will need to use at least an S.split(' =')[0] or another re.findall to find the letter.

Collectives™ on Stack Overflow

Extracting floating point numbers in a string using regex

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related