Python change all keys of a dictionary-CodePudding

How do I change all keys of a dictionary

code:

d1 = {'mango':10,
          'bananna':20,
          'grapes':30}
d1_new_keys = ['yellow mango','green banana','red grapes']
d1.keys() = d1_new_keys

present answer:

SyntaxError: can't assign to function call

expected answer:

d1 = {'yellow mango': 10, 'green bananna': 20, 'red grapes': 30}

CodePudding user response：

What you're doing is trying to set the function d1.keys() to a list thus the error. The best way to do this would be with dictionary comprehension:

d1 = {k: v for (k, v) in zip(d1_new_keys, d1.values()}

This would essentially create a new dictionary and set it equal to d1 where the keys come from the d1_new_keys list and the values come from the original d1

CodePudding user response：

Dictionaries are not ordered lists, so you can't just change the keys.

What you have to do, is build a new dictionary with the new keys.

d1 = {'mango':10, 'bananna':20, 'grapes':30}
d1_new_keys = {
    'mango': 'yellow mango',
    'bananna': 'green banana',
    'grapes':'red grapes' }
d2 = {}
for d in d1:
    if d in d1_new_keys:
        d2[d1_new_keys[d]] = d1[d]
d1 = d2

CodePudding user response：

To update the dict (without creating a new one):

d1 = {'mango':10, 'bananna':20, 'grapes':30}

d1_current_keys = list(d1.keys())
d1_new_keys = ['yellow mango','green banana','red grapes']

for current_key_ix, new_key in enumerate(d1_new_keys):
    d1[new_key] = d1.pop(d1_current_keys[current_key_ix])

NOTE: beware of depending on the order of the keys.