The pipe | character in the re module is used as the OR operator to match any one of a series of alternate patterns. It is also known as alternation.
For example, the pattern cat|dog matches either "cat" or "dog". If the pattern is matched against the string "I have a cat and a dog", it will match both "cat" and "dog".
Here's an example to illustrate the use of the pipe operator:
import retext = "I have a cat and a dog"pattern = "cat|dog"matches = re.findall(pattern, text)print("Matches:", matches) |
In this example, we are trying to match either "cat" or "dog" in a given text. We are using the pattern cat|dog with the pipe operator to create two alternate patterns. The findall() function returns a list of all the matched patterns.
The output of this program is:
Matches: ['cat', 'dog'] |
As you can see, the findall() function has returned a list containing both "cat" and "dog" as the matched patterns.
The pipe operator can also be used with other regular expression operators and quantifiers. For example, the pattern (cat|dog)fish matches either "catfish" or "dogfish", but not "fish" or "catdogfish".
import retext = "I have a catfish and a dogfish, but not a fish or a catdogfish"pattern = "(cat|dog)fish"matches = re.findall(pattern, text)print("Matches:", matches) |
In this example, we are trying to match either "catfish" or "dogfish" in a given text. We are using the pattern (cat|dog)fish with the pipe operator to create two alternate patterns. The findall() function returns a list of all the matched patterns.
The output of this program is:
Matches: ['catfish', 'dogfish'] |
As you can see, the findall() function has returned a list containing both "catfish" and "dogfish" as the matched patterns, but not "fish" or "catdogfish".