Iterate Over Two Dictionaries in Python
Python dictionaries are powerful data structures that allow you to store data in a key-value format. This makes them ideal for storing data that is related in some way, such as the prices of items in a store or the names and addresses of customers.
In some cases, you may need to iterate over two dictionaries at the same time. For example, you might want to compare the values in two dictionaries or combine the data from two dictionaries into a single dictionary.
There are a few different ways to iterate over two dictionaries in Python.
One way is to use the zip() function.
The zip() function takes two or more iterables and returns a single iterator that contains tuples of corresponding elements from each iterable.
>>> d = {'a': 5, 'b': 6, 'c': 3}
>>> d2 = {'a': 6, 'b': 7, 'c': 3}
>>> for (k, v), (k2, v2) in zip(d.items(), d2.items()):
... print(k, v)
... print(k2, v2)
a 5
a 6
c 3
c 3
b 6
b 7
Another way to iterate over two dictionaries in Python is to use the itertools.izip() function.
The itertools.izip() function is similar to the zip() function, but it returns an iterator of tuples of corresponding elements from each iterable.
This can be useful if you need to iterate over the dictionaries multiple times.
>>> from itertools import izip
>>> d = {'a': 5, 'b': 6, 'c': 3}
>>> d2 = {'a': 6, 'b': 7, 'c': 3}
>>> for (k, v), (k2, v2) in izip(d.items(), d2.items()):
... print(k, v)
... print(k2, v2)
a 5
a 6
c 3
c 3
b 6
b 7
Finally, you can also iterate over two dictionaries in Python using a for loop.
This is the most straightforward way to iterate over two dictionaries, but it can be less efficient than using the zip() or itertools.izip() functions.
>>> d = {'a': 5, 'b': 6, 'c': 3}
>>> d2 = {'a': 6, 'b': 7, 'c': 3}
>>> for k in d:
... print(k, d[k])
... print(k, d2[k])
a 5
a 6
c 3
c 3
b 6
b 7