Regular Expressions 101

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"
[\w\-][\w\-\.]+@[\w\-][\w\-\.]+[a-zA-Z]{1,4}
"
i
Match a single character present in the list below
[\w\-]
\w matches any word character (equivalent to [a-zA-Z0-9_])
\- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
Match a single character present in the list below
[\w\-\.]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
\- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
@ matches the character @ with index 6410 (4016 or 1008) literally (case insensitive)
Match a single character present in the list below
[\w\-]
\w matches any word character (equivalent to [a-zA-Z0-9_])
\- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
Match a single character present in the list below
[\w\-\.]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
\- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
Match a single character present in the list below
[a-zA-Z]
{1,4} matches the previous token between 1 and 4 times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case insensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case insensitive)
Global pattern flags
i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])
Your regular expression does not match the subject string.

Regular Expression
No Match

r"
"
i

Test String