Método pop() del diccionario de Python

El método pop() del diccionario de Python elimina y devuelve el elemento especificado del diccionario.

Sintaxis: dict.pop(clave, def)

Parámetros: 

• key : La clave cuyo par clave-valor debe devolverse y eliminarse.
• def: el valor predeterminado que se devolverá si la clave especificada no está presente.

Devuelve: valor asociado al par clave-valor eliminado, si la clave está presente. 
Valor predeterminado si se especifica si la clave no está presente. 
KeyError, si la clave no está presente y no se especifica el valor predeterminado. 

Ejemplo del método pop() del diccionario de Python

Ejemplo 1: Pop un elemento del diccionario

# Python 3 code to demonstrate
# working of pop()
 
# initializing dictionary
test_dict = {"Nikhil": 7, "Akshat": 1, "Akash": 2}
 
# Printing initial dict
print("The dictionary before deletion : " + str(test_dict))
 
# using pop to return and remove key-value pair.
pop_ele = test_dict.pop('Akash')
 
# Printing the value associated to popped key
print("Value associated to popped key is : " + str(pop_ele))
 
# Printing dictionary after deletion
print("Dictionary after deletion is : " + str(test_dict))

Producción : 

The dictionary before deletion : {'Nikhil': 7, 'Akshat': 1, 'Akash': 2}
Value associated to popped key is : 2
Dictionary after deletion is : {'Nikhil': 7, 'Akshat': 1}

Ejemplo 2: Primer elemento emergente del diccionario de Python

# Python 3 code to demonstrate
# working of pop()
 
# initializing dictionary
test_dict = {"Nikhil": 7, "Akshat": 1, "Akash": 2}
 
# Printing initial dict
print("The dictionary before deletion : " + str(test_dict))
 
# using pop to return and remove key-value pair.
pop_first = test_dict.pop("Nikhil")
 
# Printing the value associated to popped key
print("Value associated to popped key is : " + str(pop_first))
 
# Printing dictionary after deletion
print("Dictionary after deletion is : " + str(test_dict))

Producción:

The dictionary before deletion : {'Nikhil': 7, 'Akshat': 1, 'Akash': 2}
Value associated to popped key is : 7
Dictionary after deletion is : {'Akshat': 1, 'Akash': 2}

Ejemplo 3: Pop un elemento que no está presente en el diccionario

El comportamiento de la función pop() es diferente cuando la clave no está presente en el diccionario. En este caso, devuelve el valor predeterminado proporcionado o KeyError en caso de que no se proporcione el valor predeterminado.

# Python 3 code to demonstrate
# working of pop() without key
 
# initializing dictionary
test_dict = {"Nikhil": 7, "Akshat": 1, "Akash": 2}
 
# Printing initial dict
print("The dictionary before deletion : " + str(test_dict))
 
# using pop to return and remove key-value pair
# provided default
pop_ele = test_dict.pop('Manjeet', 4)
 
# Printing the value associated to popped key
# Prints 4
print("Value associated to popped key is : " + str(pop_ele))
 
# using pop to return and remove key-value pair
# not provided default
pop_ele = test_dict.pop('Manjeet')
 
# Printing the value associated to popped key
# KeyError
print("Value associated to popped key is : " + str(pop_ele))

Producción : 

The dictionary before deletion : {'Nikhil': 7, 'Akshat': 1, 'Akash': 2}
Value associated to popped key is : 4
Traceback (most recent call last):
  File "main.py", line 20, in 
    pop_ele = test_dict.pop('Manjeet')
KeyError: 'Manjeet'