Python Zip Dictionary: How To Convert List To Dictionary:
In Python, lists are sequential collections of items. They’re simple and flexible and don’t require extra pointers or indexes to track. If you have a list of numbers and you want to store that list in a dictionary, you might think you’d need to write code like this:
Lists are one of the more common data structures for use in Python. Using lists, it is quite easy to make a list of lists. When you need to do more with a list, however, you typically have to resort to lists of lists. This blog will take a look at how to convert a list to a list of dictionaries.
stocks = ['reliance', 'infosys', 'tcs']
prices = [2175, 1127, 2750]
dictionary = dict(zip(stocks, prices))
print(dictionary)
Output:
{'reliance': 2175, 'infosys': 1127, 'tcs': 2750}
Dictionary Comprehension:
Lists are a great default storage for short-lived types in Python. They are also a great building block for many iterators. Here we will create a dictionary from two sequences of items.When we are working with a list, we might need to create a dictionary from our list. And sometimes we might be asked to convert a list of items into a dictionary. In Python, we can use the dict() and zip() methods to convert a list into a dictionary. This blog will show you how to use the dict() and zip() methods.
Syntax:
dictionary = {key: value for vars in iterable}
Example #1:
stocks = ['reliance', 'infosys', 'tcs']
prices = [2175, 1127, 2750]
new_dict = {stocks: prices for stocks, prices in zip(stocks, prices)}
print(new_dict)
Output:
{'reliance': 2175, 'infosys': 1127, 'tcs': 2750}
How to convert list to dictionary using list comprehension and dict() function:
Dictionaries have some really handy methods for accessing and modifying the dictionary that is being used. One particular method is the dict() method. This will take any sequence of items and return a dictionary. The dict() method is used to create a dictionary from a list of items. The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
The dict() and zip() functions are a staple for many types of data structures. While they are very helpful, they can be difficult to understand. Here, we’ll cover the basics of using dict and zip in Python.
If you want to create a dictionary from two sequences and you want the dict() and zip() method to be as fast as possible, use the dict(zip(keys, values)) constructor.
Example #2:
print({i : chr(65+i) for i in range(4)})
# Output - {0 : 'A', 1 : 'B', 2 : 'C', 3 : 'D'}
How do I convert two lists into a dictionary?
The dict() and zip() methods share a lot of similarities. The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
The dict(zip(keys, values)) function creates a dictionary that is an alias of the zip function. It takes two sequences and maps them to the dictionary. The dict(zip(keys, values)) function needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
Example #1:
keys = ['a', 'b', 'c']
values = [1, 2, 3]
dictionary = dict(zip(keys, values))
print(dictionary)
Output:
{'a': 1, 'b': 2, 'c': 3}
Example #2:
keys = ['a', 'b', 'c']
values = [1, 2, 3]
result = {k: v for k, v in zip(keys, values)}
print(result)
#Output
# {'a': 1, 'b': 2, 'c': 3}
If you have a list of values and a list of keys and you want to create a dictionary that links the two together, you have a few options. One option is to write a list comprehension like this:Dictionary is a data type that is used to store and retrieve values in a safe and efficient way. In this blog post, we will cover the process of creating a dictionary from one sequence of key-value pairs. We will also cover the use of the dict() and zip() method to convert a list of keys to a dictionary.
Example #3:
generator_expression = dict((k, v) for k, v in zip(keys, values))
print(generator_expression)
#Output
# {'a': 1, 'b': 2, 'c': 3}
Example #4:
dict = {keys[i]: values[i] for i in range(len(keys))}
print(dict)
#Output
# {'a': 1, 'b': 2, 'c': 3}
When converting a list to a dictionary using the dict() and zip() methods, the dict(zip(keys, values)) needs to be created one time. The dict() function remains global, but the dict(zip(keys, values)) function is not. This makes dict(zip(keys, values)) a one time global look up each for dict and zip. The dict(zip(keys, values)) needs to be created in order to use the dict() function. Still, the dict(zip(keys, values)) doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
Example #5:
keys = ('name', 'age', 'food')
values = ('Monty', 42, 'spam')
dic = {k:v for k,v in zip(keys, values)}
print(dic)
#Output
#{'name': 'Monty', 'age': 42, 'food': 'spam'}
Example #6:
List1 = ['This', 'is', 'a', 'list']
List2 = ['Put', 'this', 'into', 'dictionary']
d = {List1[n]: List2[n] for n in range(len(List1))}
print(d)
#Output
#{'This': 'Put', 'is': 'this', 'a': 'into', 'list': 'dictionary'}
You can convert a list of key-value pairs to a dictionary by using the dict() function, and then you can use the zip() function to convert the dictionary to a list of key-value pairs.Dictionaries are data structures that store a collection of key-value pairs. They are the simplest possible form of associative array and are widely used in programming languages like Python, JavaScript, and C#. You can create a dictionary from two sequences using the dict() and zip() methods. It is useful to use these methods when you want to save a list of tuples into a dictionary. To create a dictionary from two sequences, use the dict() and zip() method. The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
Example #7:
keys = ['name', 'age', 'food']
values = ['Monty', 42, 'spam']
dic = {}
c = 0
for i in keys:
dic[i] = values[c]
c += 1
print(dic)
#Output
#{'name': 'Monty', 'age': 42, 'food': 'spam'}
Example #8:
l1 = [1,2,3,4,5]
l2 = ['a','b','c','d','e']
d1 = {}
for l1_ in l1:
for l2_ in l2:
d1[l1_] = l2_
l2.remove(l2_)
break
print (d1)
#Output
#{1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e'}
Lists are ordered sequences of items. A list can be anything from the result of an operation, to a queue of tasks, to a list of values that can be used in a function application. Dictionaries are collections of key-value pairs. Dictionaries are created using the dict() function and the zip() function. If a list is a sequence of items of any type, and the list has a unique item, then a dictionary can be created. Here are a few examples to illustrate how to convert a list to a dictionary.
Often you may want to convert a list of values into a dictionary. This can be done with the dict() and zip() method. With the dict() and zip() method, you need to provide the one-time global lookup each for dict and zip. However, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications. To create a dictionary from two sequences, use the dict() and zip() method.
Example #9:
y = [1,2,3,4]
x = ["a","b","c","d"]
# This below is a brute force method
obj = {}
for i in range(len(y)):
obj[y[i]] = x[i]
print(obj)
#Output
#{1: 'a', 2: 'b', 3: 'c', 4: 'd'}
Example #10:
# Recursive approach
obj = {}
def map_two_lists(a,b,j=0):
if j < len(a):
obj[b[j]] = a[j]
j +=1
map_two_lists(a, b, j)
return obj
res = map_two_lists(x,y)
print(res)
#Output
#{1: 'a', 2: 'b', 3: 'c', 4: 'd'}
Convert a list of lists to a dictionary
Python dictionaries should be your first choice for storing sets of related data. Dictionaries are not just for lists. Dictionaries are also for tuples and sets. The dict(zip(keys, values)) creates a dict from two sequences of two-item tuples, using the zip method. If a dict is what you want, use dict(zip(keys, values)) to create it. It’s as simple as that. Python’s zip() method can be used to create a dictionary from two sequences.The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.The dict(zip(keys, values)) method needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
Example #1:
x = [['A', 'B', 'C'],
[100, 90, 80],
[88, 99, 111],
[45, 56, 67],
[59, 61, 67],
[73, 79, 83],
[89, 97, 101]]
dict1={}
for i,k in enumerate( x[0]):
dict1[k]=[x1[i] for x1 in x[1:]]
print(dict1)
#{'A': [100, 88, 45, 59, 73, 89], 'B': [90, 99, 56, 61, 79, 97], 'C': [80, 111, 67, 67, 83, 101]}
Example #2:
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', '2,000', '2,000', '2,000']]
header, *data = zip(*temp)
result = [dict(zip(header, i)) for i in data]
Output:
[{'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'}]
convert list with same values to dict – smart zip (python)
Python has a zip function that builds a dictionary from two sequences. This is a neat way to create data structures with a lot of keys, but it’s not perfect. In the following code, we use the dict() and zip() methods to create a dictionary from two sequences. The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. The dict(zip(keys, values)) needs the one-time global lookup each for dict and zip. Still, it doesn’t create any needless intermediary data structures or deal with local lookups in function applications.
Python lets you create a dictionary from two sequences by using the dict() and zip() methods. This method uses a global lookup each for dict and zip, but it doesn’t create any needless intermediary data structures or deal with local lookups in function applications. A dictionary is a data structure that maps keys to values. It can be created from a list or tuple
Example #1:
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', '2,000', '2,000', '2,000']]
header, *data = zip(*temp)
result = [dict(zip(header, i)) for i in data]
Output:
[{'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'}]
Example #2:
from collections import Counter, defaultdict
data = ['apples', 400, 'sweets', 300, 'apples', 750]
def convert(A):
result = defaultdict(Counter)
it = iter(A)
for fruit, count in zip(it, it):
if fruit not in result:
result[fruit] = count
else:
result[fruit] += count
return result
print(convert(data))
#Output
# defaultdict(<class 'collections.Counter'>, {'apples': 1150, 'sweets': 300})
Example #3:
lst = ['apples', 400, 'sweets', 300, 'apples', 750]
dct = {}
for frt, mny in zip(lst[::2], lst[1::2]):
dct[frt] = dct.get(frt, 0) + mny
print(dct)
#Output:
#{'apples': 1150, 'sweets': 300}
Conclusion:
Dictionary comprehension is an elegant and concise way to create dictionaries. For example, we can use the above example to create a dictionary from two lists.The zip(fields, values) method returns an iterator that generates two-items tuples. If you call dict() on that iterator, you can create the dictionary you need. The items of the first list become the dictionary’s keys, and the elements second list represent the values in the dictionary.The list and dictionary are among the robust data structures in Python. Converting from each other is the most common task you have ever faced in Python development. you often create a dictionary from two different but closely related sequences. An easy way to approach this is to use the dict() and zip() methods together.
