Python: Match a string that contains only upper and lowercase letters, numbers, and underscores - w3resource
GitHub - bansalnitish/REGularEXpressions: All you need to know about Regular Expressions collected at a place !
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Python: Match a string that contains only upper and lowercase letters, numbers, and underscores - w3resource
![c# - Regex expression to verify that a string only contains letters, numbers, underscores and dashes - Stack Overflow c# - Regex expression to verify that a string only contains letters, numbers, underscores and dashes - Stack Overflow](https://i.stack.imgur.com/zg4dl.png)