Regular Expressions 101

Explanation
Pro

(?m)applies the following effective flags to the remainder of the pattern: gm

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

^start of line

Non-Capturing Group(?:from[ ]+(\S+)[ ]+)?

?repeats the group contents below at most once:

fromthe literal text from (case sensitive)

Character Class[ ]+

+matches at least one character from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

Group 1(\S+)

\S+any character that is not Unicode whitespace, repeated at least once

Character Class[ ]+

+matches at least one character from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

importthe literal text import (case sensitive)

Character Class[ ]+

+matches at least one character from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

Group 2(\S+)

\S+any character that is not Unicode whitespace, repeated at least once

Character Class[ ]*

*matches any number of characters from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

(?m)^(?:from[ ]+(\S+)[ ]+)?import[ ]+(\S+)[ ]*$

New

from abc.lmn import pqr
from abc.lmn import pqr as xyz
import abc
import abc as xyz

from abc.lmn import pqr
from abc.lmn import pqr as xyz
import abc
import abc as xyz