regex101: Python Match Workspace

Non-Capturing Group(?:\.?)

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 1([\w\-_+#~!$&\'\.]+(?<!\.)@(?<!\.)[\w]+[\w\-\.]*\.[a-zA-Z-]{2,3})

Character Class[\w\-_+#~!$&\'\.]+

+matches at least one character from the set below:

\wa Unicode word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

!the literal ! (33₁₀ / 41₈ / 21₁₆)

$the literal $ (36₁₀ / 44₈ / 24₁₆)

&the literal & (38₁₀ / 46₈ / 26₁₆)

\'the literal ' (39₁₀ / 47₈ / 27₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negative Lookbehind(?<!\.)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Negative Lookbehind(?<!\.)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[\w]+

+matches at least one character from the set below:

\wa Unicode word character

Character Class[\w\-\.]*

*matches any number of characters from the set below:

\wa Unicode word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-zA-Z-]{2,3}

{2,3}matches between 2 and 3 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:[^\w])

Negated Character Class[^\w]

\wa Unicode word character

Global pattern flags

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

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

Search reference

Regular Expression

(?:\.?)([\w\-_+#~!$&\'\.]+(?<!\.)@(?<!\.)[\w]+[\w\-\.]*\.[a-zA-Z-]{2,3})(?:[^\w])

New

VALID EMAILS:

davida@yahoo.com, davida-100@yahoo.com, davida.100@yahoo.com, davida111@davida.com, davida-100@davida.net, davida.100@davida.com.au, davida@1.com, davida@gmail.com.com, davida+100@gmail.com, davida-100@yahoo-test.com  valid special char ~@davidalberto.com hey@ucl.ac.uk, "this..one"@gmail.com, h.e.y@gmail.com, 

the "." at the start should be ignored .davida@davida.com,
suffix should be ignored davida@gmail.com.1a
prefix should be ignored davida@davida@gmail.com,

INVALID EMAILS:

davida, davida@.com.my, davida123.@gmail.a, davida123@gmail.a, davida123@.com, davida123@.com.com, davida()*@gmail.com, davida@%*.com, davida.@gmail.com,  
tld is too long davida@gmail.comnnnnnnnn 

INVALID EMAILS - TODO:

adjacent "." should not be valid davida..2002@gmail.com
some images a@bg.png  1x@cover.gif

HIDDEN EMAILS:

somethingatgmail.com 
something at gmail.com  something AT gmail.com 
asdf ( at ) gmail.com yoooo (at) gmail.com

HIDDEN EMAILS - TODO:

this at that dot com
this [at] that [dot] com


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Regular Expressions 101

Regular Expression

Substitution