Convert tuple to dictionary python

For the tuple, t = ((1, 'a'),(2, 'b')) dict(t) returns {1: 'a', 2: 'b'}

Is there a good way to get {'a': 1, 'b': 2} (keys and vals swapped)?

Ultimately, I want to be able to return 1 given 'a' or 2 given 'b', perhaps converting to a dict is not the best way.

asked Sep 24, 2010 at 1:04

JakeJake

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Try:

>>> t = ((1, 'a'),(2, 'b'))
>>> dict((y, x) for x, y in t)
{'a': 1, 'b': 2}

answered Sep 24, 2010 at 1:07

Greg HewgillGreg Hewgill

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4

A slightly simpler method:

>>> t = ((1, 'a'),(2, 'b'))
>>> dict(map(reversed, t))
{'a': 1, 'b': 2}

answered Oct 5, 2011 at 20:46

jterracejterrace

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4

Even more concise if you are on python 2.7:

>>> t = ((1,'a'),(2,'b'))
>>> {y:x for x,y in t}
{'a':1, 'b':2}

answered Mar 2, 2013 at 21:20

autholykosautholykos

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>>> dict([('hi','goodbye')])
{'hi': 'goodbye'}

Or:

>>> [ dict([i]) for i in (('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14)) ]
[{'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}]

Smi

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answered Feb 14, 2013 at 0:05

GunnarssonGunnarsson

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0

If there are multiple values for the same key, the following code will append those values to a list corresponding to their key,

d = dict()
for x,y in t:
    if(d.has_key(y)):
        d[y].append(x)
    else:
        d[y] = [x]

answered Apr 10, 2016 at 1:15

psunpsun

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Here are couple ways of doing it:

>>> t = ((1, 'a'), (2, 'b'))

>>> # using reversed function
>>> dict(reversed(i) for i in t)
{'a': 1, 'b': 2}

>>> # using slice operator
>>> dict(i[::-1] for i in t)
{'a': 1, 'b': 2}

answered Jan 2, 2018 at 14:26

Vlad BezdenVlad Bezden

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Sometimes you might need to convert a tuple to dict object to make it more readable.
In this article, we will try to learn how to convert a list of tuples into a dictionary. Here we will find two methods of doing this.
Examples:

Input : [("akash", 10), ("gaurav", 12), ("anand", 14), 
         ("suraj", 20), ("akhil", 25), ("ashish", 30)]
Output : {'akash': [10], 'gaurav': [12], 'anand': [14], 
          'ashish': [30], 'akhil': [25], 'suraj': [20]}

Input : [('A', 1), ('B', 2), ('C', 3)]
Output : {'B': [2], 'A': [1], 'C': [3]}

Input : [("Nakul",93), ("Shivansh",45), ("Samved",65),
             ("Yash",88), ("Vidit",70), ("Pradeep",52)]
Output : {'Nakul': [93], 'Shivansh': [45], 'Samved': [65], 
            'Yash': [88], 'Vidit': [70], 'Pradeep': [52]}

Input : [('Sachin', 10), ('MSD', 7), ('Kohli', 18), ('Rohit', 45)]
Output : {'Sachin': 10, 'MSD': 7, 'Kohli': 18, 'Rohit': 45}

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Method 1 : Use of setdefault()

Here we have used the dictionary method setdefault() to convert the first parameter to key and the second to the value of the dictionary. setdefault(key, def_value) function searches for a key and displays its value and creates a new key with def_value if the key is not present. Using the append function we just added the values to the dictionary.

Example 1:

def Convert(tup, di):

    for a, b in tup:

        di.setdefault(a, []).append(b)

    return di

tups = [("akash", 10), ("gaurav", 12), ("anand", 14), 

     ("suraj", 20), ("akhil", 25), ("ashish", 30)]

dictionary = {}

print (Convert(tups, dictionary))

Output:

{'akash': [10], 'gaurav': [12], 'anand': [14], 
 'ashish': [30], 'akhil': [25], 'suraj': [20]}

Example 2:

list_1=[("Nakul",93), ("Shivansh",45), ("Samved",65),

           ("Yash",88), ("Vidit",70), ("Pradeep",52)]

dict_1=dict()

for student,score in list_1:

    dict_1.setdefault(student, []).append(score)

print(dict_1)

Output:

{'Nakul': [93], 'Shivansh': [45], 'Samved': [65], 'Yash': [88], 'Vidit': [70], 'Pradeep': [52]}

Method 2 : Use of dict() method

Example 1:

def Convert(tup, di):

    di = dict(tup)

    return di

tups = [("akash", 10), ("gaurav", 12), ("anand", 14), 

    ("suraj", 20), ("akhil", 25), ("ashish", 30)]

dictionary = {}

print (Convert(tups, dictionary))

Output:

{'anand': 14, 'akash': 10, 'akhil': 25, 
 'suraj': 20, 'ashish': 30, 'gaurav': 12}

Example 2:

print (dict([('Sachin', 10), ('MSD', 7), ('Kohli', 18), ('Rohit', 45)]))

Output:

{'Sachin': 10, 'MSD': 7, 'Kohli': 18, 'Rohit': 45}

This is a simple method of conversion from a list or tuple to a dictionary. Here we pass a tuple into the dict() method which converts the tuple into the corresponding dictionary.

Can I put a tuple in a dictionary?

How do you create a dictionary from a list of tuples?

Can tuple be dictionary Python?

Which of the following function convert a sequence of tuples to dictionary in Python?