in can be used to check if there is an entry with a certain key within a dictionary.

Example 1

p is Person
"database" in p.values

This returns true if an entry "database" is present in the persons values. If there is no such entry, it will return false.

Example 2

"Last Name" in {"First Name": "Thorben"}

This creates a simple dictionary with just one entry with the key "First Name". We then check if the entry "Last Name" exists, which is does not, so this results in a false value.

Last updated