Few mistakes when using Python dictionary Last Updated : 06 Mar, 2019 Comments Improve Suggest changes Like Article Like Report Usually, A dictionary is a collection which is unordered, changeable and indexed. In Python, dictionaries are written with curly brackets, and they have keys and values. Each key-value pair in a Dictionary is separated by a 'colon', whereas each key is separated by a ‘comma’. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} print(my_dict) Output: {1: 'Geeks', 2: 'For', 3: 'Geeks'} We generally use dictionaries to access the items with its key value, inside square brackets. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} print(my_dict[1]) print(my_dict[2]) print(my_dict[3]) Output: Geeks For Geeks The common operations of dictionaries are: To get the values of the dictionary we use values() method. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} print(my_dict.values()) Output: dict_values(['Geeks', 'For', 'Geeks']) To get the keys of the dictionary we use keys() method. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} print(my_dict.keys()) Output: dict_keys([1, 2, 3]) To add a new entry into the dictionary Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} my_dict[4]='Python' print(my_dict) Output: {1: 'Geeks', 2: 'For', 3: 'Geeks', 4: 'Python'} To change the value of the entry Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} my_dict[3]='Python' print(my_dict) Output: {1: 'Geeks', 2: 'For', 3: 'Python'} To delete an entry from dictionary Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} del my_dict[3] print(my_dict) Output: {1: 'Geeks', 2: 'For'} To copy the dictionary Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} my_dict1 = my_dict print(my_dict1) Output: {1: 'Geeks', 2: 'For', 3: 'Geeks'} To remove all entries. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} my_dict.clear() print(my_dict) Output: {} To find the number of entries. Python3 1== my_dict = {1: 'Geeks', 2: 'For', 3:'Geeks'} z = len(my_dict) print(z) Output: 3 Common mistakes while using dicts and overcomes To access the value of the key, we generally use dict_name[key_name] instead we should use get() method to get rid of the exceptions thrown all throughout your code. To update the value of the key, we generally use dict_name[key_name]='new_value' instead we should update(key=value) method to get rid of the exceptions thrown all throughout your code. To copy the dictionary, we generally use dict_name = new_dict_name instead we should use copy() method to get rid of the exceptions thrown all throughout your code. When not to use dicts Dicts are useful but they're not the only associative array structure in Python. Often there is a more specialised container type like set, tuple etc. Numeric values with different types can be equal (e.g. 1 == 1.0), in which case they represent the same key. Comment More infoAdvertise with us Next Article Few mistakes when using Python dictionary S suman_ptnl Follow Improve Article Tags : Python python-dict Practice Tags : pythonpython-dict Similar Reads Update Nested Dictionary - Python A nested dictionary in Python is a dictionary that contains another dictionary (or dictionaries) as its value. Updating a nested dictionary involves modifying its structure or content by:Adding new key-value pairs to any level of the nested structure.Modifying existing values associated with specifi 4 min read Python dictionary (Avoiding Mistakes) What is dict in python ? Python dictionary is similar to hash table in languages like C++. Dictionary are used to create a key value pair in python. In place of key there can be used String Number and Tuple etc. In place of values there can be anything. Python Dictionary is represented by curly brac 4 min read Python Nested Dictionary A Dictionary in Python works similarly to the Dictionary in the real world. The keys of a Dictionary must be unique and of immutable data types such as Strings, Integers, and tuples, but the key values can be repeated and be of any type. What is Python in Nested Dictionary? Nesting Dictionary means 3 min read Python Dictionary Exercise Basic Dictionary ProgramsPython | Sort Python Dictionaries by Key or ValueHandling missing keys in Python dictionariesPython dictionary with keys having multiple inputsPython program to find the sum of all items in a dictionaryPython program to find the size of a DictionaryWays to sort list of dicti 3 min read Dictionary with Tuple as Key in Python Dictionaries allow a wide range of key types, including tuples. 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In this article, we will explore the Top 30 Python Dictionary interview questions to help you prepare for technical interviews.Table of ContentBasic Python Dictionary Interview QuestionsIntermediate Python Dictionary In 7 min read Python Dictionary get() Method Python Dictionary get() Method returns the value for the given key if present in the dictionary. If not, then it will return None (if get() is used with only one argument).Python Dictionary get() Method Syntax:Syntax : Dict.get(key, Value)Parameters: key: The key name of the item you want to return 3 min read How to implement Dictionary with Python3? This program uses python's container called dictionary (in dictionary a key is associated with some information). This program will take a word as input and returns the meaning of that word. Python3 should be installed in your system. If it not installed, install it from this link. Always try to ins 3 min read Dictionary has_key() - Python The has_key() method in Python was used to check whether a specified key exists in a dictionary. However, this method was removed in Python 3 and the preferred approach to check for a key's existence is by using the in keyword. In Python 2.7, the has_key() method was commonly used, like so:Pythond = 3 min read Like