In Python, the popitem method, on dictionaries, removes the last key: value pair entered in the dictionary. Furthermore, this method adds the deleted pair as a tuple.
This method has no parameters, so its syntax is simply this:
d.popitem()
If the dictionary has no elements the method returns a keyError.
Python popitem – first example
In this first example we delete the last element from our student dictionary.
Here is a possible implementation of the proposed algorithm:
student = {
'name': 'Cristina', 'age': 20, 'mail': 'info@codingcreativo.it'
}
student.popitem()
print(student)
In output we will see this result:
{'name': 'Cristina', 'age': 20}
Try the above code in the online compiler which you will find at the following link: online Python compiler.
Now we also print the deleted element always using the Python popitem method on the dictionaries:
student = {
'name': 'Cristina', 'age': 20, 'mail': 'info@codingcreativo.it'
}
del_student = student.popitem()
print(del_student)
print(student)
In this case, the output generated is the following:
('mail', 'info@codingcreativo.it')
{'name': 'Cristina', 'age': 20}
Python popitem – second example
This time we will try to delete from an empty dictionary.
student = {}
del_student = student.popitem()
print(del_student)
print(student)
An error message will be returned, noting that the dictionary is empty:
Traceback (most recent call last): File “/tmp/sessions/95c2c3a3544875f9/main.py”, line 2, in <module> del_student = student.popitem() KeyError: ‘popitem(): dictionary is empty’
It is very important to know how to read errors, so experiment every time you are faced with a new topic.
Conclusion
In this lesson we talked about the popitem method on dictionaries in Python, later we will see how to put these methods into practice.
