Regular Expressions 101

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"
([0-9]|[a-zA-Z]+| )*
"
1st Capturing Group
([0-9]|[a-zA-Z]+| )*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
1st Alternative
[0-9]
Match a single character present in the list below
[0-9]
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
2nd Alternative
[a-zA-Z]+
Match a single character present in the list below
[a-zA-Z]
+ matches the previous token between one and unlimited 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 sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
3rd Alternative
matches the character with index 3210 (2016 or 408) literally (case sensitive)
Your regular expression does not match the subject string.

Regular Expression
No Match

r"
"

Test String