Python re.match: How to specific "OR" match

Question

Suppose I have a data file:

# cat 1.txt
#$$!#@#VM - This is VM$^#^#$^$^
%#%$%^SAS - This is SAS&%^#$^$
!@#!@%^$^MD - This is MD!@$!@%$

Now I want to filter the words starting with VM and SAS (excluding MD)

Expected results:

VM - This is VM
SAS - This is SAS

I am using this code but all lines are shown.

import re

f = open("1.txt", "r")

for line in f:
    p = re.match(r'.+?((SAS|VM)[-a-zA-Z0-9 ]+).+?', line)
    if p:
        print (p.groups()[0])

In regular expression, I can use (pattern1|pattern2) to match either pattern1 or pattern2 But in re.match, parenthesis is used for matching the pattern.

How to specify "Either Match" in re.match() function?

Answer 1

This is one approach.

Ex:

import re

with open(filename) as infile:
    for line in infile:
        line = re.sub(r"[^A-Za-z\-\s]", "", line.strip())
        if line.startswith(("VM", "SAS")):
            print(line)

Output:

VM - This is VM
SAS - This is SAS

Answer 2

Try it like this:

with open('1.txt') as f:
    for line in f:
        extract = re.match('.+?((SAS|VM)[-a-zA-Z0-9 ]+).+?', line)
        if extract:
            print(extract.group(1))