4 Answers

+ 4

| is a bitwise or
It operates on binary digits
For instance if you had the number 10 and 13 and you ORed them.
10 = 0000 1010 in binary (as byte)
13 = 0000 1101 in binary (as byte)
The result would be
15 = 0000 1111 in binary (as byte)
A | B | result
0 | 0 | 0
0 | 1 | 1
1 | 0 | 1
1 | 1 | 1
if either of the bit are 1 the resulting bit is 1, otherwise 0.
print(10 | 13) # outputs 15

+ 3

"|" means 3 things in Python:
Either a bitwise-OR operator,
or a set-combine operator,
or "OR" in regex.

+ 2

It's a bitwise operator and it's functionality is similar to the logical || operator. If either of the bits value are 1 then it returns 1 otherwise 0. It's logical operator || countersign works by returning an integral boolean of 1 if either of the expression is truthy otherwise 0

+ 2

1- a union operator which used to combine two sets to form a new one containing elements in either = {}.union() method
2 - in regular expressions it means or