create dictionary from given list in python

Question

I have a python list , and I want to create a dictionary with word as a key and number as a value. what is the efficient way of doing this. Here is the my code:

['a',100,'b',200,'c',300,'d',400]

I want to convert it into dictionary like {'a':100,'b':200,'c':300,'d':400} please help me.

Can this help you - https://stackoverflow.com/questions/4576115/convert-key1-val1-key2-val2-to-a-dict — Daniel Hao, Oct 17 '21 at 11:12
I have tried following code my_list = ['a',100,'b',200,'c',300,'d',400] v1 = [] v2 = [] for chr in my_list: if type(chr) == chr.isalpha(): v1.append(chr) else: v2.append(chr) ans = zip(v1,v2) print(ans) — Dheeraj Surwase, Oct 17 '21 at 11:14

score 0 · Answer 1 · answered Oct 17 '21 at 11:11

0

Apply your list for this convert function.

def Convert(lst):
    res_dct = {lst[i]: lst[i + 1] for i in range(0, len(lst), 2)}
    return res_dct
    

lst = ['a', 100, 'b', 200, 'c', 300]
print(Convert(lst))

answered Oct 17 '21 at 11:11

Ashish Dawkhar

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score 0 · Answer 2 · answered Oct 17 '21 at 11:12

You can just loop through the list, and add to dictionary as key element at index, and as value element at index + 1. I write sample code for you to understand easier, I didn't use any builtin methods for conversion, I don't is there any methods for what you want, but there is always solution. Code:


list1 = ['a',100,'b',200,'c',300,'d',400]

dict1 = { }

# this is for loup which is used for "conversion"
for i in range(0, len(list1), 2):
    dict1[list1[i]] = list1[i+1]
    
for i in dict1:
    print("Key : " + i + " Value : " + str(dict1[i]))

score 0 · Answer 3 · answered Oct 17 '21 at 11:14

0

Pythonic way:

>>> lst = ['a',100,'b',200,'c',300,'d',400]
>>> dict(zip(lst[::2], lst[1::2]))
{'d': 400, 'c': 300, 'a': 100, 'b': 200}

answered Oct 17 '21 at 11:14

Hackaholic

19,069
5
54
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@DheerajSurwase if like my solution you can accept it as the answer – Hackaholic Oct 17 '21 at 17:35

score 0 · Answer 4 · answered Oct 17 '21 at 11:15

That's just one efficient line

{ key: value for key, value in zip(x[::2], x[1::2]) } # x is the input list

Explanation:

x[::2] - takes all even index elements of the list: slice the list at zero through the end with step of 2 (['a', 'b', 'c', 'd'])
x[1::2] - takes all odd index elements of the list: slice the list at index 1 through the end with step of 2 ([100, 200, 300, 400])
zip(x[::2], x[1::2]) - extracts a tuple of elements from both the inputs ([('a',100), ('b', 200), ('c', 300), ('d', 400)])
{ key: value for key, value in zip(...) } - iterates on the (key=even elements, value=odd elements) tuples and creates the dictionary

create dictionary from given list in python

4 Answers4