Python - Change Dictionary Items

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Apart from the literal representation of dictionary, where we put comma-separated key:value pairs in curly brackets, we can create dictionary object with built-in dict() function.

Empty Dictionary

Using dict() function without any arguments creates an empty dictionary object. It is equivalent to putting nothing between curly brackets.

Example

d1 = dict()
d2 = {}
print ('d1: ', d1)
print ('d2: ', d2)

It will produce the following output −

d1: {}
d2: {}

Dictionary from List of Tuples

The dict() function constructs a dictionary from a list or tuple of two-item tuples. First item in a tuple is treated as key, and the second as its value.

Example

d1=dict([('a', 100), ('b', 200)])
d2 = dict((('a', 'one'), ('b', 'two')))
print ('d1: ', d1)
print ('d2: ', d2)

It will produce the following output −

d1: {'a': 100, 'b': 200}
d2: {'a': 'one', 'b': 'two'}

Dictionary from Keyword Arguments

The dict() function can take any number of keyword arguments with name=value pairs. It returns a dictionary object with the name as key and associates it to the value.

Example

d1=dict(a= 100, b=200)
d2 = dict(a='one', b='two')
print ('d1: ', d1)
print ('d2: ', d2)

It will produce the following output −

d1: {'a': 100, 'b': 200}
d2: {'a': 'one', 'b': 'two'}