How to set all Dictionary values to 0 in Python

# Table of Contents

1. Set all dictionary values to 0 in Python
2. Set all dictionary values to 0 using a dict comprehension
3. Set all dictionary values to 0 using a for loop

# Set all dictionary values to 0 in Python

Use the dict.fromkeys() method to set all dictionary values to 0.

The dict.fromkeys() method creates a new dictionary with keys from the provided iterable and values set to the supplied value.

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my_dict = {
    'bobby': 1,
    'hadz': 2,
    'com': 3,
}

my_dict = dict.fromkeys(my_dict, 0)
print(my_dict)  # 👉️ {'bobby': 0, 'hadz': 0, 'com': 0}

We used the dict.fromkeys() method to set all dictionary values to zero.

The dict.fromkeys() method takes an iterable and a value and creates a new dictionary with keys from the iterable and values set to the provided value.

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# 👇️ {'a': None, 'b': None, 'c': None}
print(dict.fromkeys({'a': 'bobby', 'b': 'hadz', 'c': 'com'}))

# 👇️ {'a': 0, 'b': 0, 'c': 0}
print(dict.fromkeys({'a': 'bobby', 'b': 'hadz', 'c': 'com'}, 0))

If you'd rather not change the dictionary in place, assign the output of calling dict.fromkeys() to a new variable.

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my_dict = {
    'bobby': 1,
    'hadz': 2,
    'com': 3,
}

new_dict = dict.fromkeys(my_dict, 0)
print(new_dict)  # 👉️ {'bobby': 0, 'hadz': 0, 'com': 0}

# Set all dictionary values to 0 using a dict comprehension

Alternatively, you can use a dict comprehension.

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my_dict = {
    'bobby': 1,
    'hadz': 2,
    'com': 3,
}

my_dict = {key: 0 for key in my_dict}
print(my_dict)  # 👉️ {'bobby': 0, 'hadz': 0, 'com': 0}

Dict comprehensions are very similar to list comprehensions.

On each iteration, we set the value of the key to zero and return the result.

Alternatively, you can use a simple for loop.

# Set all dictionary values to 0 using a for loop

This is a three-step process:

1. Use a for loop to iterate over the dictionary.
2. Set the value of each key to zero.
3. After the last iteration, all of the values in the dictionary will be set to 0.

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my_dict = {
    'bobby': 1,
    'hadz': 2,
    'com': 3,
}

for key in my_dict:
    my_dict[key] = 0

print(my_dict)  # 👉️ {'bobby': 0, 'hadz': 0, 'com': 0}

We used a for loop to iterate over the dictionary.

On each iteration, we set the value of the current key to 0.

If you'd rather not modify the original dictionary, declare a separate variable.

Copied!
my_dict = {
    'bobby': 1,
    'hadz': 2,
    'com': 3,
}

new_dict = {}

for key in my_dict:
    new_dict[key] = 0

print(new_dict)  # 👉️ {'bobby': 0, 'hadz': 0, 'com': 0}

Instead of modifying the existing dictionary, we set all keys to 0 in a new dictionary.

I've also written an article on how to sum all values in a dictionary.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

• Swap the keys and values in a Dictionary in Python
• Check if all values in a Dictionary are equal in Python
• How to Replace values in a Dictionary in Python
• Get multiple values from a Dictionary in Python
• Join the Keys or Values of Dictionary into String in Python
• Multiply the Values in a Dictionary in Python