Python dict get key by index

Python dictionary find a key by value

In this Python tutorial, we will learn about the Python dictionary to find a key by value. Also, we will discuss the below examples:

• Python dictionary find key by max value.
• Python dictionary get Key value by index
• Python dictionary find key using value
• Python dictionary get key value pair
• Python dictionary find key with maximum value
• Python dictionary get key if value exists

Python dictionary find a key by value

• Here we can see how to get the key by value in Python.
• We can perform this task by various methods, Here is the list of some that we can use.
  • By using list.index()
  • By using dict.items() method
  • By using list comprehension method

  By using list.index() method

  The index method always returns the index position in a list or dictionary.

  Source Code:

  to_dictionary = new_ke_lis = list(to_dictionary.keys()) new_val = list(to_dictionary.values()) new_pos = new_val.index(610) # value from dictionary print("Get a key by value:",new_ke_lis[new_pos])

  Here is the Screenshot of the following given code

  

  By using dict.items() method

  This method returns a dictionary view object that displays the list of a dictionary in the key-value pair form.

  my_dict= for key,value in my_dict.items(): if value==9: print("key by value:",key)

  

  By using list comprehension method

  In Python to get the key with the maximum value, we can use the list comprehension method. This method will help the user to execute each element along with the for loop to iterate each item.

  new_dictionary= t= print("key by value:",t)

  

  Python dictionary find key by max value

  • Let us see how to find the key by the maximum value.
  • By using the max() function we will find the key with maximum value in Dictionary.
  • To do this task first we will initialize a dictionary and assign them a key-value pairs element. Now use a max() function to get the key with maximum value.

  new_dict= new_ke = max(new_dict, key=new_dict.get) print("To get Key maxvalue:",new_ke)

  Here is the implementation of the following given code

  

  Another example to get the key with max value

  By using the itemgetter() function and operator module we can easily get the key. The itemgetter() function returns an object that collects an item from its operand using the operator module.

  Let’s take an example and check how to get the key by using the itemgetter() function.

  import operator my_dict1 = new_max_key = max(my_dict1.items(), key = operator.itemgetter(1))[0] print("key with highest value:\n",new_max_key)

  Here is the Screenshot of the following given code

  

  By using lambda function

  In Python, the lambda function did not need any name, they are nameless. They are used to declare a one-line function. In this example, you just need to give the function a value and then provide an expression.

  In this example, we have to check how to find a key with maximum value using the lambda function

  my_dict2 = ma_value = max(my_dict2, key= lambda i: my_dict2[i]) print(ma_value)

  

  Python dictionary get key value by index

  • Let us see how to get a key-value pair by index in the dictionary.
  • To perform this task we can use the enumerator method. This is an in-built function in Python that allows the user to check how many iterations have occurred. This method can be used directly for loops and convert them into a list.
  • Let’s take an example and check how to get key-value pair by index.

  my_new_dict = get_key = 'i' new_search_key='l' new_var = list(my_new_dict.items()) output = [ab for ab, new_key in enumerate(new_var) if new_key[0] == get_key] result2 = [ab for ab, new_key in enumerate(new_var) if new_key[0] == new_search_key] print("Get index value of key : ",output) print("Get index value of key : ",result2) 

  Here is the execution of the following given code

  

  Another example to check how to get key-value index by using dict() method

  Source Code:

  dict1 = ind_lis = list(dict1) new_key = ind_lis[1] print("Get key-value by index:",new_key)

  Here is the Output of the following given code

  

  Python dictionary find key using value

  In Python to find a key using the value, we can collect the key from a value by comparing all the values and get the specific key. In this example, we can use dict.items() method.

  Let’s take an example and check how to find a key by using the value.

  from typing import TextIO def new_ke(val): for k, new_va in to_dictionary.items(): if val == new_va: return k return to_dictionary = print("Key exist in dictionary:",new_ke(72)) print("key doesnot contain in dictionary:",new_ke(48))

  Here is the Screenshot of the following given code

  

  Python dictionary get key value pair

  • To get key-value pair in the dictionary we can easily use the enumerator method.
  • This method helps the user to access the named index of the position of the key-value element in the dictionary.

  dictionary1 = for x in enumerate(dictionary1.items()): print("key-value pair in dictionary:",x)

  Here is the implementation of the following given code

  

  Another example to check how to get key value pair

  To perform this particular task we can easily use the list comprehension method. This method returns the elements in the form of key-value pairs and it will display the result as tuples of key and value in the list.

  you_dictionary = print ("key-value pairs are : ") print([(m, you_dictionary[m]) for m in you_dictionary])

  Here is the Screenshot of the following given code

  

  Python dictionary find key with maximum value

  To find the key with the maximum value we can easily use the function values() and keys().

  to_dict2 = new_value = list(to_dict2.values()) new_key = list(to_dict2.keys()) print(new_key[new_value.index(max(new_value))])

  Here is the execution of the following given code

  

  Python dictionary get key if value exist

  from typing import TextIO def exe_ke(val): for x, new_va in your_dict.items(): if val == new_va: return x return your_dict = print("Value exist in dictionary:",exe_ke(149)) print("value doesnot exist in dictionary:",exe_ke(456))

  

  You may also like reading the following articles.

  In this Python tutorial, we have learned about the Python dictionary to find a key by value. Also, we have also discussed the below examples:

  • Python dictionary find key by max value.
  • Python dictionary get Key value by index
  • Python dictionary find key using value
  • Python dictionary get key value pair
  • Python dictionary find key with maximum value

  I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.

  Источник

  Python Dictionary Index

  

  1. Access the Keys From a Dictionary Using the Index
  2. Access the Values From a Dictionary Using the Index in Python
  3. Access the Key-Value Pairs From a Dictionary Using the Index in Python

  Dictionaries are used for storing key-value pairs in Python. In general, we cannot access a dictionary using the index of their elements for other collections like a list or an array.

  Before Python 3.7, dictionaries were orderless. Each key-value is given a random order in a dictionary. We can use the OrderedDict() method from the collections module in these cases. It preserves the order in which the key-value pairs are added to the dictionary.

  In Python 3.7 and up, the dictionaries were made order-preserving by default.

  We can access the keys, values, and key-value pairs using the index in such dictionaries where the order is preserved.

  Access the Keys From a Dictionary Using the Index

  We will use the keys() method, which returns a collection of the keys. We can use the index to access the required key from this collection after converting it to a list.

  Remember to use the list() function with the keys() , values() and items() function. It is because that they do not return traditional lists and do not allow access to elements using the index.

  The following demonstrates this.

  d = <> d['a'] = 0 d['b'] = 1 d['c'] = 2 keys = list(d.keys()) print(keys[1]) 

  When working below Python 3.7, remember to use the OrderedDict() method to create the required dictionary with its order maintained. For example,

  from collections import OrderedDict d1 = OrderedDict() d1['a'] = 0 d1['b'] = 1 d1['c'] = 2 keys = list(d1.keys()) print(keys[1]) 

  Access the Values From a Dictionary Using the Index in Python

  When we want to return a collection of all the values from a dictionary, we use the values() function.

  d = <> d['a'] = 0 d['b'] = 1 d['c'] = 2 values = list(d.values()) print(values[1]) 

  Access the Key-Value Pairs From a Dictionary Using the Index in Python

  The items() function returns a collection of all the dictionary’s key-value pairs, with each element stored as a tuple.

  The index can be used to access these pairs from the list.

  d = <> d['a'] = 0 d['b'] = 1 d['c'] = 2 values = list(d.items()) print(values[1]) 

  Remember to use the OrderedDict() function with all the methods if your version of Python doesn’t preserve the order of the dictionary.

  Manav is a IT Professional who has a lot of experience as a core developer in many live projects. He is an avid learner who enjoys learning new things and sharing his findings whenever possible.

  Related Article — Python Dictionary

  Источник

  Читайте также:  Маркетинг в социальных сетях для бизнеса | Bussines.ru