Convert List into a Dictionary

Convert list into a dictionary

Using the usual grouper recipe, you could do:

Python 2:

d = dict(itertools.izip_longest(*[iter(l)] * 2, fillvalue=""))

Python 3:

d = dict(itertools.zip_longest(*[iter(l)] * 2, fillvalue=""))

How to convert a list to a dictionary with indexes as values?

You can get the indices of a list from the built-in enumerate. You just need to reverse the index-value map and use a dictionary comprehension to create a dictionary:

>>> lst = ['A', 'B', 'C']
>>> {k: v for v, k in enumerate(lst)}
{'A': 0, 'C': 2, 'B': 1}

How do I convert list into dictionary in Python?

What you have is a list of dict(s). So, you could do it as follows.

  • If values is the name of list variable, then values[i] gives you access to a dictionary stored at index i.
  • The dict.get(key, None) will either return a value or None when the key does not exist. This may allow you to avoid unwanted error when a certain field is absent.
# Use of dict.get(key, "value-when-no-match")
# is safer than directly calling dict[key]
# BUT, this depends on your design/logic/requirements.
values[0].get('what', None)

An Observation

Since "allDay": true was in your sample data, I assume that most likely you are trying to read this from a JSON file. If that is the case, and if you are using json library in python, that could be easily dealt with using json.load(), json.loads().

Dummy Data

Note that you had a boolean value (for "allDay") as true >> Python expects True with a capital T.

values = [
"what": "Drink",
"allDay": True,
"id": 12,
"when": "2020-05-13",
"end": "2020-05-13"

"what": "Eat",
"allDay": True,
"id": 14,
"when": "2020-05-14",
"end": "2020-05-14"

Converting Dictionary to List?

Your problem is that you have key and value in quotes making them strings, i.e. you're setting aKey to contain the string "key" and not the value of the variable key. Also, you're not clearing out the temp list, so you're adding to it each time, instead of just having two items in it.

To fix your code, try something like:

for key, value in dict.iteritems():
temp = [key,value]

You don't need to copy the loop variables key and value into another variable before using them so I dropped them out. Similarly, you don't need to use append to build up a list, you can just specify it between square brackets as shown above. And we could have done dictlist.append([key,value]) if we wanted to be as brief as possible.

Or just use dict.items() as has been suggested.

Converting a list to dictionary in python

A dict comprehension will do.

my_list = [2, 3, 5, 7, 11]
my_dict = {k: 0 for k in my_list} # {2:0 , 3:0 , 5:0 , 7:0 , 11:0}

Even if you are not familiar at all with comprehensions you could still do an explicit for-loop:

my_dict = {}
for k in my_list:
my_dict[k] = 0

Simple way to convert list into dict with False values

As enke suggested you can use fromkeys method of dict class to convert the list or any other iterable into a dict by a fixed value for all keys.

In [1]: a = [1,2, "hello"]                                                                                                                                                      

In [2]: dict.fromkeys(a, False)
Out[2]: {1: False, 2: False, 'hello': False}

And also you can use dict comprehension as below:

In [1]: a = [1,2, "hello"]                                                                                                                                                      

In [2]: {key: False for key in a}
Out[2]: {1: False, 2: False, 'hello': False}

Convert a list of lists to a dictionary

You have zip as an option:

wanted = {a[0]: list(a[1:]) for a in zip(*x)}

Or if you're familiar with unpacking:

wanted = {k: v for k, *v in zip(*x)}

Convert list of strings to dictionary


a = ['Tests run: 1', ' Failures: 0', ' Errors: 0']

d = {}
for b in a:
i = b.split(': ')
d[i[0]] = i[1]

print d


{' Failures': '0', 'Tests run': '1', ' Errors': '0'}

If you want integers, change the assignment in:

d[i[0]] = int(i[1])

This will give:

{' Failures': 0, 'Tests run': 1, ' Errors': 0}

convert list of lists to dictionary


>>> temp = [['header1', '4', '8', '16', '32', '64', '128', '256', '512', '243,6'], ['media_range', '1,200', '2,400', '4,800', '4
...: ,800', '6,200', '38,400', '76,800', '153,600', '160,000'], ['speed', '300', '600', '1,200', '2,000', '2,000', '2,000', '2,0
...: 00', '2,000', '2,000']]
>>> keys = [l[0] for l in temp]
>>> values = [l[1:] for l in temp]
>>> dicts = [dict(zip(keys, sub)) for sub in zip(*values)]
>>> dicts
[{'header1': '4', 'media_range': '1,200', 'speed': '300'},
{'header1': '8', 'media_range': '2,400', 'speed': '600'},
{'header1': '16', 'media_range': '4,800', 'speed': '1,200'},
{'header1': '32', 'media_range': '4,800', 'speed': '2,000'},
{'header1': '64', 'media_range': '6,200', 'speed': '2,000'},
{'header1': '128', 'media_range': '38,400', 'speed': '2,000'},
{'header1': '256', 'media_range': '76,800', 'speed': '2,000'},
{'header1': '512', 'media_range': '153,600', 'speed': '2,000'},
{'header1': '243,6', 'media_range': '160,000', 'speed': '2,000'}]

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