Python del from dict

Python — Remove Dictionary Items

There are several methods to remove items from a dictionary:

Example

The pop() method removes the item with the specified key name:

Example

The popitem() method removes the last inserted item (in versions before 3.7, a random item is removed instead):

Example

The del keyword removes the item with the specified key name:

Example

The del keyword can also delete the dictionary completely:

thisdict = <
«brand»: «Ford»,
«model»: «Mustang»,
«year»: 1964
>
del thisdict
print(thisdict) #this will cause an error because «thisdict» no longer exists.

Example

The clear() method empties the dictionary:

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Python Remove Key from Dictionary – How to Delete Keys from a Dict

Shittu Olumide

Dictionaries are a useful data type in Python for storing data in a key-value format. And there are times when you might need to remove a particular key-value pair from a dictionary.

You’ll learn some dictionary basics, as well as how to delete keys, in this tutorial.

How to Write a Dict in Python

Dictionaries are denoted by curly braces <> and the key-value pairs are separated by colons : . For example, the following code initializes a dictionary with three key-value pairs:

You can also initialize dictionaries using the built-in dict() function. For example:

my_dict = dict(apple=2, banana=3, orange=5) 

Now I’ll teach you how to securely remove keys from a Python dictionary. When I say «securely,» I mean that if the key doesn’t actually exist in the dictionary, the code won’t throw an error.

We’ll discover how to accomplish this using the del keyword, the pop() method, and the popitem() method. Finally, you’ll see how to use Python to remove multiple keys from a dictionary.

How to Remove a Key from a Dict Using the del Keyword

The most popular method for removing a key:value pair from a dictionary is to use the del keyword. You can also use it to eliminate a whole dictionary or specific words.

Simply use the syntax shown below to access the value you need to delete:

Let’s have a look at an example:

Members = del Members["Doe"] print(Members) 

How to Remove a Key from a Dict Using the pop() Method

Another technique to remove a key-value pair from a dictionary is to use the pop() method. The syntax is shown below:

dictionary.pop(key, default_value) 

My_Dict = data = My_Dict.pop(1) print(data) print(My_Dict) 

How to Remove a Key from a Dict Using the popitem() Function

The built-in popitem() function eliminates the the last key:value pair from a dictionary. The element that needs to be removed cannot be specified and the function doesn’t accept any inputs.

The syntax looks like this:

Let’s consider and example for a better understanding.

# initialize a dictionary My_dict = # using popitem() Deleted_key = My_dict.popitem() print(Deleted_key) 

As you can see, the function removed the last key:value pair – 5: «Black» – from the dictionary.

How to Remove Multiple Keys from a Dict

You can easily delete multiple keys from a dictionary using Python. The .pop() method, used in a loop over a list of keys, is the safest approach for doing this.

Let’s examine how we can supply a list of unique keys to remove, including some that aren’t present:

My_dict = #define the keys to remove keys = ['Sam', 'John', 'Doe'] for key in keys: My_dict.pop(key, None) print(My_dict) 

One thing to note is that in the pop() method inside the loop, we pass in None and the default value, just to make sure no KeyError is printed if a key doesn’t exist.

How to Remove All Keys from a Dict Using the clear() Method

You can use the clear() method to remove all key-value pairs from a dictionary. The syntax is as follows:

Colors = Colors.clear() print(Colors) 

Conclusion

For removing a key-value pair or several key-value pairs from a dictionary, we discussed a variety of Python methods in this article.

You can do so using the del keyword, which is the most common method of removing a key-value pair from a dictionary. The pop() method is useful when we need to remove a key-value pair and also get the value of the key-value pair. Using the popitem() function, we can remove the final key-value pair in a dictionary.

Also, if you need to remove all key:value pairs in a dictionary, you can use the clear() method.

Let’s connect on Twitter and on LinkedIn. You can also subscribe to my YouTube channel.

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Remove an item from a dictionary in Python (clear, pop, popitem, del)

In Python, to remove an item (element) from a dictionary ( dict ), use the clear() , pop() , popitem() methods or the del statement. You can also remove items that satisfy the conditions using the dictionary comprehensions.

See the following article for how to add items to a dictionary.

Remove all items from a dictionary: clear()

The clear() method removes all items from a dictionary, making it empty.

d = 'k1': 1, 'k2': 2, 'k3': 3> d.clear() print(d) # <> 

Remove an item by a key and return its value: pop()

By specifying a key to the pop() method, the item is removed and its value is returned.

d = 'k1': 1, 'k2': 2, 'k3': 3> removed_value = d.pop('k1') print(d) # print(removed_value) # 1 

By default, specifying a non-existent key raises a KeyError .

d = 'k1': 1, 'k2': 2, 'k3': 3> # removed_value = d.pop('k4') # print(d) # KeyError: 'k4' 

If you pass the second argument, its value is returned if the key does not exist. The dictionary remains unchanged.

d = 'k1': 1, 'k2': 2, 'k3': 3> removed_value = d.pop('k4', None) print(d) # print(removed_value) # None 

Remove an item and return its key and value: popitem()

The popitem() method removes an item from the dictionary and returns its key and value as a tuple, (key, value) .

Since Python 3.7, the order of elements in the dictionary is preserved. As a result, popitem() removes elements in LIFO (last in, first out) order.

A KeyError is raised for an empty dictionary.

d = 'k1': 1, 'k2': 2> k, v = d.popitem() print(k) print(v) print(d) # k2 # 2 # k, v = d.popitem() print(k) print(v) print(d) # k1 # 1 # <> # k, v = d.popitem() # KeyError: 'popitem(): dictionary is empty' 

Remove an item by a key from a dictionary: del

You can also use the del statement to delete an item from a dictionary.

d = 'k1': 1, 'k2': 2, 'k3': 3> del d['k2'] print(d) # 

You can specify and remove multiple items.

d = 'k1': 1, 'k2': 2, 'k3': 3> del d['k1'], d['k3'] print(d) # 

If a non-existent key is specified, a KeyError is raised.

d = 'k1': 1, 'k2': 2, 'k3': 3> # del d['k4'] # print(d) # KeyError: 'k4' 

Remove items that satisfy a condition: Dictionary comprehensions

To remove items that meet certain conditions from a dictionary, use dictionary comprehensions, which are the dictionary equivalent of list comprehensions.

«Removing items that satisfy a condition» is equivalent to «extracting items that do not satisfy the condition».

For example, to remove items with odd values, you can extract items with even values. The same applies to the opposite case.

d = 'apple': 1, 'banana': 10, 'orange': 100> dc = k: v for k, v in d.items() if v % 2 == 0> print(dc) # dc = k: v for k, v in d.items() if v % 2 == 1> print(dc) # 

The items() method of dict is used to extract keys and values.

You can also specify conditions based on the keys.

dc = k: v for k, v in d.items() if k.endswith('e')> print(dc) # dc = k: v for k, v in d.items() if not k.endswith('e')> print(dc) # 

You can use and and or to specify multiple conditions.

dc = k: v for k, v in d.items() if v % 2 == 0 and k.endswith('e')> print(dc) # 

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