In Python, a dictionary is one of the built-in data structures (the others are tuples, lists, and sets). A dictionary is a collection of key:value pairs and you can use them to solve various programming problems.

Dictionaries are very flexible to work with. You can get the keys and values separately, or even together.

This article is about looping over a dictionary with the for loop, but you can also loop through a dictionary with three methods:

  • the key() method: gets you the keys in a dictionary
  • the values() method: gets you the values in a dictionary
  • the items() method: gets you both the keys and values in a dictionary

In the example below, I use those 3 methods to get the keys, values, and items of the dictionary.

states_tz_dict = {
    'Florida': 'EST and CST',
    'Hawaii': 'HST',
    'Arizona': 'DST',
    'Colorado': 'MST',
    'Idaho': 'MST and PST',
    'Texas': 'CST and MST',
    'Washington': 'PST',
    'Wisconsin': 'CST'
}

# Keys
states_keys = states_tz_dict.keys()
print(states_keys) # dict_keys(['Florida', 'Hawaii', 'Arizona', 'Colorado', 'Idaho', 'Texas', 'Washington', 'Wisconsin'])

#  Values
tz_values = states_tz_dict.values()
print(tz_values) # dict_values(['EST and CST', 'HST', 'DST', 'MST', 'MST and PST', 'CST and MST', 'PST', 'CST']) 

# Keys and values
states_tz_dict_items = states_tz_dict.items()
print(states_tz_dict_items) # dict_items([('Florida', 'EST and CST'), ('Hawaii', 'HST'), ('Arizona', 'DST'), ('Colorado', 'MST'), ('Idaho', 'MST and PST'), ('Texas', 'CST and MST'), ('Washington', 'PST'), ('Wisconsin', 'CST')])

That's some iterations we did. But you can also loop through a dictionary with a for loop. That's what we are going to look at in this tutorial.

What We'll Cover

How to Iterate through a Dictionary with a for Loop

With the Python for loop, you can loop through dictionary keys, values, or items. You can also loop through the dictionary and put the key:value pair in a list of tuples. We are going to look at them one by one.

How to Iterate through Dictionary Keys with a for Loop

Remember how I got the keys of the dictionary with the keys() method in the first part of this article? You can use the same method in a for loop and assign each of the keys to a variable we can call k:

states_tz_dict = {
    'Florida': 'EST and CST',
    'Hawaii': 'HST',
    'Arizona': 'DST',
    'Colorado': 'MST',
    'Idaho': 'MST and PST',
    'Texas': 'CST and MST',
    'Washington': 'PST',
    'Wisconsin': 'CST'
}

for k in states_tz_dict.keys():
    print(k)

# Result:
# Florida   
# Hawaii    
# Arizona   
# Colorado  
# Idaho     
# Texas     
# Washington
# Wisconsin

How to Iterate through Dictionary Values with a for Loop

You can use the values() method in a for loop too, and assign the values to a variable you can call v:

states_tz_dict = {
    'Florida': 'EST and CST',
    'Hawaii': 'HST',
    'Arizona': 'DST',
    'Colorado': 'MST',
    'Idaho': 'MST and PST',
    'Texas': 'CST and MST',
    'Washington': 'PST',
    'Wisconsin': 'CST'
}

for v in states_tz_dict.values():
    print(v)
    
# Result:
# EST and CST
# HST        
# DST        
# MST        
# MST and PST
# CST and MST
# PST        
# CST

How to Iterate through Dictionary Items with a for Loop

The items() method comes in handy in getting the keys and values inside a for loop. This time around, you have to assign two variables instead of one:

states_tz_dict = {
    'Florida': 'EST and CST',
    'Hawaii': 'HST',
    'Arizona': 'DST',
    'Colorado': 'MST',
    'Idaho': 'MST and PST',
    'Texas': 'CST and MST',
    'Washington': 'PST',
    'Wisconsin': 'CST'
}

for k, v in states_tz_dict.items():
    print(k,"--->", v)

# Result:
# Florida ---> EST and CST
# Hawaii ---> HST
# Arizona ---> DST        
# Colorado ---> MST       
# Idaho ---> MST and PST  
# Texas ---> CST and MST  
# Washington ---> PST     
# Wisconsin ---> CST

Note: You can use any letter for the variable(s) in a for loop. It doesn't have to be k or v, or k, v.

How to Loop through a Dictionary and Convert it to a List of Tuples

To convert a dictionary to a list of tuples in Python, you still have to use the items() method inside a for loop.

But this time around, you have to surround the loop with square brackets. You also have to assign the loop to a separate variable and wrap the variable for both keys and values in brackets:

states_tz_dict = {
    'Florida': 'EST and CST',
    'Hawaii': 'HST',
    'Arizona': 'DST',
    'Colorado': 'MST',
    'Idaho': 'MST and PST',
    'Texas': 'CST and MST',
    'Washington': 'PST',
    'Wisconsin': 'CST'
}

list_of_tuples = [(k, v) for k, v in states_tz_dict.items()]
print(list_of_tuples)

# Result: [('Florida', 'EST and CST'), ('Hawaii', 'HST'), ('Arizona', 'DST'), ('Colorado', 'MST'), ('Idaho', 'MST and PST'), ('Texas', 'CST 
# and MST'), ('Washington', 'PST'), ('Wisconsin', 'CST')]

Conclusion

In this tutorial, we looked at how to iterate through a dictionary with the for loop.

If you don’t want to use a for loop, you can also use any of the keys(), values(), or items() methods directly like I did in the first part of this article.

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