Menu
I know that _ cannot be matched by \W while any other punctuation can.
As the docs state: \w is a set of alphanumeric characters and the underscore.
At the same time:
I have always been confused by this but never actually bothered to question why.
Does it have to do with the special role that _ plays in Python?
574
Following are different places where _ is used in Python: Multiple time we do not want return values at that time assign those values to Underscore. It used as throwaway variable. Python has their by default keywords which we can not use as the variable name. To avoid such conflict between python keyword and variable we use underscore after name
The underscore character ( _ ) represents a single character to match a pattern from a word or string. More than one ( _ ) underscore characters can be used to match a pattern of multiple characters. To get 'cust_code', 'cust_name', 'cust_city' and 'cust_country' from the table 'customer' with following conditions -
Underscore Operator. The underscore character ( _ ) represents a single character to match a pattern from a word or string. More than one ( _ ) underscore characters can be used to match a pattern of multiple characters. Example.
Leading double underscore tell python interpreter to rewrite name in order to avoid conflict in subclass.Interpreter changes variable name with class extension and that feature known as the Mangling. In Mangling python interpreter modify variable name with ___.
Lots of Python's regular expression syntax in the module re comes from Perl, which was influenced by sed and awk. The \w comes from there and has a long history.
In the original regex module (which was deprecated in Python 1.5), \w did not include _, as is evident from Python 1.4 documentation:
\wMatches any alphanumeric character; this is equivalent to the set
[a-zA-Z0-9].
P.S. While it is not very convenient can match all non-\w + _ with a character class [\W_].
162
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
