Méthode d'utilisation de dict() Python et exemples

Python built-in functions

The dict() constructor creates a dictionary in Python.

There are several forms of the dict() constructor, respectively:

class dict(**kwarg)
class dict(mapping,　**kwarg)
class dict(iterable,　**kwarg)

Note:**kwarg allows you to accept any number of keyword arguments.

Keyword arguments are parameters that start with an identifier (such as name=). Therefore, the form of keyword arguments kwarg=value passes kwarg=value to the dict() constructor to create a dictionary.

dict() does not return any value (returns None).

Example1: Create a dictionary using only keyword arguments

numbers = dict(x=5, y=0)
print('numbers =', numbers)
print(type(numbers))
empty = dict()
print('empty =', empty)
print(type(empty))

When running the program, the output is:

numbers = {'y': 0, 'x':　5}
<class 'dict'>
empty = {}
<class 'dict'>

Example2: Create a dictionary using an iterable

# Do not pass keyword arguments
numbers1　= dict([('x',　5), ('y',　-5))
print('numbers1　=' ,numbers1)
# Keyword arguments are also passed
numbers2　= dict([('x',　5), ('y',　-5], z=8)
print('numbers2　=' ,numbers2)
# zip() in Python　3Create an iterable object in
numbers3　= dict(dict(zip(['x', 'y', 'z'], [1,　2,　3])
print('numbers3　=' ,numbers3)

When running the program, the output is:

numbers1　= {'y':　-5, 'x':　5}
numbers2　= {'z':　8, 'y':　-5, 'x':　5}
numbers3　= {'z':　3, 'y':　2, 'x':　1}

Example3: Create a dictionary using mapping

numbers1　= {'x':　4, 'y':　5)
print('numbers1　=' ,numbers1)
# You do not need to use dict() in the above code
numbers2　= {'x':　4, 'y':　5}
print('numbers2　=' ,numbers2)
# Keyword arguments are also passed
numbers3　= {'x':　4, 'y':　5}, z=8)
print('numbers3　=' ,numbers3)

When running the program, the output is:

numbers1　= {'x':　4, 'y':　5}
numbers2　= {'x':　4, 'y':　5}
numbers3　= {'x':　4, 'z':　8, 'y':　5}

Recommended reading: Python dictionary and how to use them Python built-in functions