[Tut] Python Print Dictionary Without One Key or Multiple Keys

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Python Print Dictionary Without One Key or Multiple Keys

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The most Pythonic way to print a dictionary except for one or multiple keys is to filter it using dictionary comprehension and pass the filtered dictionary into the

Code:

print()

function.

There are multiple ways to accomplish this and I’ll show you the best ones in this tutorial. Let’s get started!

Recommended Tutorial: How to Filter a Dictionary in Python

Method 1: Dictionary Comprehension



Say, you have one or more keys stored in a variable

Code:

ignore_keys

that may be a list or a set for efficiency reasons.

Create a filtered dictionary without one or multiple keys using the dictionary comprehension

Code:

{k:v for k,v in my_dict.items() if k not in ignore_keys}

that iterates over the original dictionary’s key-value pairs and confirms for each key that it doesn’t belong to the ones that should be ignored.

Here’s a minimal example:

Code:

ignore_keys = {'x', 'y'} my_dict = {'x': 1, 'y': 2, 'z': 3} filtered_dict = {k:v for k,v in my_dict.items() if k not in ignore_keys} print(filtered_dict) # {'z': 3}

The

Code:

dict.items()

method creates an iterable of key-value pairs over which we can iterate.

The membership operator

Code:

k not in ignore_keys

tests if a given key doesn’t belong to the set.

The runtime complexity of the membership check is constant O(1) if you use a set for the

Code:

ignore_keys

data structure. It would be linear O(n) in the number of elements if you used a list which is not a good idea for that reason.

Note that you can also use this approach to print a dictionary except a single key by putting only one key into the ignore list.

Recommended Tutorial: Dictionary Comprehension in Python

Method 2: Simple For Loop with If Condition



A not-so-Pythonic but reasonably readable way to print a dict without one or multiple keys is to use a simple

Code:

for

loop with

Code:

if

condition to avoid all keys in the ignore list.

Here’s an example using three lines and directly printing the key-value pairs:

Code:

ignore_keys = {'x', 'y'} my_dict = {'x': 1, 'y': 2, 'z': 3} for k, v in my_dict.items(): if k not in ignore_keys: print(k, v)

The output:

Code:

z 3

Of course, you can modify the output to your own needs. See the customizations of the built-in

Code:

print()

function and its awesome arguments:

Recommended Tutorial: Python

Code:

print()

and Separator and End Arguments

My Recommendation – Use This Method!

I could have listed many more ways to solve this problem of printing a dict except one or more keys.

I have seen super inefficient ways proposed on forums that use

Code:

exclude_keys

that are list types.

I have also seen elaborate schemes to use set difference operations or more.

But I don’t recommend anything else than dict comprehension if you want to create a filtered dictionary object first and the simple

Code:

for

loop if you want to print on the fly.

That’s it.