Python Dictionary duplicate keys

In this Python tutorial, we will study about Python dictionary duplicate keys using some examples in python. Moreover, we will also cover these topics.

• Python dictionary duplicate keys
• Python dictionary copy keys
• Python dictionary remove duplicate keys
• Python copy dict remove key
• Python dictionary update duplicate keys
• Python dict copy specific keys
• Python dictionary copy keys and values

Python dictionary duplicate keys

• In this section, we will learn how to create a dictionary by using duplicate keys in list Python.
• To do this task we are going to use the concept of dict() and zip() method. These methods are available in Python and the zip() method takes iterable as a parameter where iterables can be a list of tuples.
• To create a dictionary we will use the dict() method. In Python the dict() method will check the condition if there are no values in arguments then it declares an empty dictionary.
• In this example, we have created two lists named ‘dup_lis_key’ and ‘list2’ in which we have assigned the string and integer value.
• Next, we will declare a variable ‘new_result’ and use the dict() function for creating a dictionary. Now we will consider the ‘dup_lis_key’ list as a dictionary key and ‘list2’ as a dictionary value.

Example:

dup_lis_key = ['U.S.A', 'U.S.A', 'China']
list2 = [78,16,256]

new_result = dict(zip(dup_lis_key, list2))
print("Dictionary created:",new_result)

In the above example, we have created a list in which we have assigned the duplicate country name ‘U.S.A’. Now we will check the duplicate key ‘U.S.A’ will contain in the dictionary or not.

Here is the Screenshot of the following given code.

As you can see in the Screenshot, the output displays the dictionary but it does not have duplicate keys in a dictionary because in Python dictionary does not allow duplicate keys.

If you want to get all those values from a list and store them in the dictionary then you have to use the unique key with every value.

Let’s take an example and check how to create a Python dictionary with unique keys

dup_lis_key = ['U.S.A', 'Japan', 'China']
list2 = [78,16,256]

new_result = dict(zip(dup_lis_key, list2))
print("Dictionary created:",new_result)

In the above code, we have just updated the key element from ‘U.S.A’ to ‘Japan’. Once you will execute this code it will display all the key elements along with values.

Here is the implementation of the following given code

Also, check: If not condition in Python

Python dictionary copy keys

• In this Program, we will learn how to copy keys from the Python dictionary.
• To perform this particular task, we are going to use the dict.keys() method. This is an inbuilt() method in the Python package and it is used to get the key elements from the dictionary and store them into a new list.
• In this example, we have to copy only key elements from the given dictionary. To do this task first we will create a dictionary in which we will assign the key-value pair elements. Next, we will use the dict.keys() method where dict is the dictionary name.

Syntax:

Let’s have a look at the syntax and understand the working of dict.keys() method

dict.keys()

Example:

Let’s take an example and check how to copy the key elements from a dictionary by using the dict.keys() method

Source Code:

As you can see in the Screenshot, the output displays the keys from the dictionary.

Read: Python Return Function

Python dictionary remove duplicate keys

We had already covered this topic on the Python dictionary remove in an article. You get all the information regarding how to remove duplicate keys from the Python dictionary.

Python copy dict remove key

• Here we are going to see how to remove key from copy dictionary in Python.
• By using the dict.copy() method we can easily copy the orginal dictionaary to another one and this method is a built-in function in python and it does not take any parameter. As per the program if you print the ‘new_result’ variable the output displays the shallow copy of the original dictionary.
• Now we are going to use the del keyword to remove the key from the copied dictionary and this keyword is basically used to delete items in Python.

Syntax:

Here is the Syntax of Python dict.copy() method

dict.copy()

Source Code:

my_dict = {'U.S.A':567,'China':976,'Japan':178,'Polland':289}
new_result=my_dict.copy()
print("Dictionary copy:",new_result)
del new_result['Japan']


print("Copy dictionary after removing key:",new_result)

In the above code, we have created a simple dictionary named ‘my_dict’ and assigned key-value pairs. After that, we have used the del keyword and specified the key name [‘japan’] which we want to remove from the dictionary.

Here is the implementation of the following given code

As you can see in the Screenshot the output displays that the ‘japan’ key has been removed from the dictionary.

Read: Get First Key in dictionary Python

Python dictionary update duplicate keys

• In this section, we will learn how to update duplicate keys in Python dictionary.
• To do this task we are going to use the dictionary.update() function. This function is available in Python package and it is used to update the dictionary elements(key-value) pair.
• To get detail information regarding dictionary update() function. You can refer our article “Python dictionary update“.

Syntax:

Let’s have a look at the Syntax and understand the working of the Python dictionary.update() function.

dict.update([other])

Example:

Let’s take an example and check how to update duplicate keys in the Python dictionary

Source Code:

new_dict = {'George':167, 'John':456, 'Micheal':657, 'Oliva':456, 'John':978 }

print("Duplicates keys dictionary:",new_dict)
new_dict.update({'john':891})
print("updated duplicate country value",new_dict)

In the following given code, we have created a dictionary and assigned key-value pair elements. After that, we have used the dict.update() method and pass the duplicate key as an argument.

You can refer to the below Screenshot

As you can see in the Screenshot the output displays the ‘John’ key element has been updated.

Read: Python dictionary increment value

Python dict copy specific keys

• In this example, we will discuss how to get the specific keys from a copied dictionary in Python.
• To perform this particular task first we will create a dictionary named ‘my_dictionary’ and then we are going to use the dict.copy() function for creating a shallow copy of the original dictionary.
• Next to get the specific keys from the dictionary we are going to use the dictionary comprehension method in which we have specified the key elements in a list.

Example:

my_dictionary = {'U.S.A' : 78, "United kingdom" : 56, 'Australia' : 145, 'NewZealand' : 567}

new_result=my_dictionary.copy()
print("Dictionary copy:",new_result)

new_output = dict((i, new_result[i]) for i in ['U.S.A', 'Australia']
										if i in new_result)
print("Specific keys:",new_output)

Here is the execution of the following given code.

As you can see in the Screenshot the output displays the specific keys along with values.

Also, read: Python dictionary of lists

Python dictionary copy keys and values

• In this section, we will learn how to copy keys and values in Python dictionary.
• By using the dictionary.copy() method, we can easily copy the key-value pair elements from one dictionary to another.
• To get detail information regarding dictionary update() function. You can refer our article “Python dictionary copy“.

Example:

Let’s take an example and check how to use the dictionary.copy() function in Python

Source Code:

new_dict = {'U.S.A':67, 'NewZealand':567, 'United Kingdom':156, 'China':2456, 'France':897 }

print("Original dictionary:",new_dict)
new_result = new_dict.copy()
print("Copied keys and values:",new_result)

In the above code, first, we have created a dictionary named ‘new_dict’ with some key-value pair elements. And then, we have applied the dict.copy() function and it will return a shallow copy of the given dictionary.

Here is the execution of the following given code.

You may also like to read the following Python tutorials.

• Python dictionary multiple keys
• Python dictionary extend
• Python Dictionary to CSV
• Python dictionary of tuples
• Python dictionary multiple values
• Python dictionary update() method [With Examples]
• Check if two dictionaries are equal in Python

In this tutorial, we have discussed about Python dictionary duplicate keys. Moreover, we have covered these topics.

• Python dictionary duplicate keys
• Python dictionary copy keys
• Python dictionary remove duplicate keys
• Python copy dict remove key
• Python dictionary update duplicate keys
• Python dict copy specific keys
• Python dictionary copy keys and values