Access Dictionary Values Given by User in Python

Dictionaries are a fundamental data structure in Python, providing a flexible way to store and retrieve data using key-value pairs. Accessing dictionary values is a common operation in programming, and Python offers various methods to accomplish this task efficiently. In this article, we will explore some generally used methods to access dictionary values given by the user in Python.

Example

Input:  {'name': 'geeks', 'age': 21, 'country': 'India'}
Output : Enter a key: age 
               The value for key 'age' is: 21

How to Access Dictionary Values Given by User in Python?

Below, are the methods of How to Access Dictionary Values Given by User in Python.

• Using Bracket Notation
• Using get() Method
• Using keys() Method
• Using items() Method
• Using Default Dictionary

Access Dictionary Values Given by User in Python Using Bracket Notation

In this example, the below code takes user input for a key, accesses the corresponding value from the dictionary `user_dict`, and prints it along with the key. Note that it may raise a `KeyError` if the entered key is not present in the dictionary.

Python3

user_dict = {'name': 'geeks', 'age': 21, 'country': 'India'}
key = input("Enter a key: ")

value = user_dict[key]
print(f"The value for key '{key}' is: {value}")

Output

Enter a key: age
The value for key 'age' is: 21

Access Dictionary Values Given by User in Python Using get() Method

In this example, below code, used user input to retrieve the value associated with the entered key from the dictionary `user_dict`. The `get()` method is employed to handle the case where the key is not found, providing a default value of “Key not found.” The result is then printed.

Python3

user_dict = {'name': 'geeks', 'age': 21, 'country': 'India'}
key = input("Enter a key: ")

value = user_dict.get(key, "Key not found")
print(f"The value for key '{key}' is: {value}")

Output

Enter a key: city
The value for key 'city' is: Key not found

Access Dictionary Values Given by User in Python Using keys() Method

In this example, below code prompts the user to input a key and checks if it exists in the dictionary `user_dict`. If found, it retrieves and prints the corresponding value; otherwise, it notifies the user that the key was not found in the dictionary.

Python3

user_dict = {'name': 'geeks', 'age': 21, 'country': 'India'}
key = input("Enter a key: ")

if key in user_dict.keys():
    value = user_dict[key]
    print(f"The value for key '{key}' is: {value}")
else:
    print(f"Key '{key}' not found in the dictionary.")

Output

Enter a key: name
The value for key 'name' is: geeks

Access Dictionary Values Given by User in Python Using items() Method

In this example, below code allows the user to input a key and then iterates through the key-value pairs in the dictionary `user_dict`. If the entered key is found, it prints the corresponding value; otherwise, it notifies the user that the key was not found in the dictionary.

Python3

user_dict ={'name': 'geeks', 'age': 21, 'country': 'India'}
key = input("Enter a key: ")

for k, v in user_dict.items():
    if k == key:
        print(f"The value for key '{key}' is: {v}")
        break
else:
    print(f"Key '{key}' not found in the dictionary.")

Output

Enter a key: age
The value for key 'age' is: 21

Access Dictionary Values Given by User in Python Using Default Dictionary

In this example ,In this code, the user is prompted to input a key, and a `defaultdict` with a default value of “Key not found” is created using the original dictionary `user_dict`. The value associated with the entered key is then retrieved from the `default_dict` and printed.

Python3

from collections import defaultdict

user_dict ={'name': 'geeks', 'age': 21, 'country': 'India'}
key = input("Enter a key: ")

default_dict = defaultdict(lambda: "Key not found", user_dict)
value = default_dict[key]
print(f"The value for key '{key}' is: {value}")

Output

Enter a key: country
The value for key 'country' is: India

Conclusion

In Conclusion , Accessing dictionary values in Python is a common operation, and these five methods provide flexibility and options based on different scenarios. Choosing the appropriate method depends on the specific requirements of your code. Whether using basic bracket notation, get(), keys(), items(), or defaultdict, Python offers versatile tools to make dictionary value access efficient and error-resistant.