How to create a Dictionary from Separate Lists of Keys and Values in Python

In Python, a dictionary is a collection of key-value pairs. You can create a dictionary by enclosing a comma-separated list of key-value pairs in curly braces {}. For example, the following code creates a dictionary that maps country names to their capital cities:

countries = {
    'India': 'New Delhi',
    'United States': 'Washington D.C.',
    'United Kingdom': 'London',
}

Method 1: zip function

Sometimes, you may have two separate lists of keys and values that you want to use to create a dictionary. In this case, you can use the zip function to combine the two lists into a single iterable, and then pass the result to the dict function to create the dictionary.

Here's an example of how you can use zip and dict to create a dictionary from separate lists of keys and values:

keys = ['India', 'United States', 'United Kingdom']
values = ['New Delhi', 'Washington D.C.', 'London']

countries = dict(zip(keys, values))
print(countries)  # {'India': 'New Delhi', 'United States': 'Washington D.C.', 'United Kingdom': 'London'}

Method 2: dict comprehension

Alternatively, you can use a dictionary comprehension to create the dictionary. A dictionary comprehension is similar to a list comprehension, but it allows you to create a dictionary by iterating over an iterable and constructing key-value pairs.

Here's how you can use a dictionary comprehension to create a dictionary from separate lists of keys and values:

keys = ['India', 'United States', 'United Kingdom']
values = ['New Delhi', 'Washington D.C.', 'London']

countries = {key: value for key, value in zip(keys, values)}
print(countries)  # {'India': 'New Delhi', 'United States': 'Washington D.C.', 'United Kingdom': 'London'}
You can also use the enumerate function to iterate over the lists and create the dictionary. enumerate returns a tuple containing the index and the value for each element in the list, so you can use it to create a dictionary that maps the indices of the keys and values to the corresponding keys and values.

Here's an example of how you can use enumerate and a dictionary comprehension to create a dictionary from separate lists of keys and values:

```python
keys = ['India', 'United States', 'United Kingdom']
values = ['New Delhi', 'Washington D.C.', 'London']

countries = {key: values[i] for i, key in enumerate(keys)}
print(countries)  # {'India': 'New Delhi', 'United States': 'Washington D.C.', 'United Kingdom': 'London'}

Method 3: for-loop

Finally, you can use a for loop to iterate over the lists and add the key-value pairs to an empty dictionary.

Here's an example of how you can use a for loop to create a dictionary from separate lists of keys and values:

keys = ['India', 'United States', 'United Kingdom']
values = ['New Delhi', 'Washington D.C.', 'London']

countries = {}
for i in range(len(keys)):
    countries[keys[i]] = values[i]

print(countries)  # {'India': 'New Delhi', 'United States': 'Washington D.C.', 'United Kingdom': 'London'}

You can also use the for loop in combination with the zip function to simplify the code:

keys = ['India', 'United States', 'United Kingdom']
values = ['New Delhi', 'Washington D.C.', 'London']

countries = {}
for key, value in zip(keys, values):
    countries[key] = value

print(countries)  # {'India': 'New Delhi', 'United States': 'Washington D.C.', 'United Kingdom': 'London'}