Python dictionary length – Everything you needs to know

In this Python tutorial, we will discuss the Python dictionary length. Here we will also cover the below examples:

  • Python dictionary length of values
  • Python dictionary length of keys
  • Python dictionary list length
  • Python get length of empty dictionary
  • Python dictionary length limit
  • Python nested dictionary length
  • Python dictionary string length
  • Python dictionary size limit
  • Python dictionary word length
  • Python dictionary key length performance

Python dictionary length

  • To check the length of a Python dictionary, we can easily use Python’s built-in function len().
  • This function gives the number of lengths which is available in the dictionary in the form of key-value pairs.
  • Len() function always return the number of iterable items given in the dictionary. This method actually acts as a counter which is automatically defined the data.

Syntax:

Here is the Syntax of len() function

len(dict)

Example:

Let’s take an example and check how to find the length of a dictionary by using the len() method.

my_dict = {"Micheal":20,"george":30,"james":40}
print("Length of dictionary:",len(my_dict))

Here is the Screenshot of the following given code.

Python dictionary length
Python dictionary length

Another example to check how to find the length of a dictionary using the instance() method in Python.

  • Instance method takes two parameters. The first argument is object. We need to pass a object as an argument. The object may be an float, integer or string. The second argument is class/type. This method will help the user to find the length of a dictionary.
  • In this example, first we will create a variable whose name is “length“.To check whether it is an instance of dictionary we can iterate through all the given values which is present in the dictionary.

Example:

my_dict ={
       'Emp_info':
           {
               'emp_name':'james',
               'L_name':'potter'
           },
       'emp_Age':40,
       'emp_position':'Developer',
       'addr':
           {
           
           'emp_City':'Newyork',
           'Country':'U.S.A'
           }       
      }
emp_length = len(my_dict)
for x in my_dict.values():
      
 
    if isinstance(x, dict):
        emp_length += len(x)
print("length of the dictionary:", emp_length)

The screenshot of the execution is given below.

Python dictionary length by instance method
Python dictionary length by instance method

Read: Python while loop multiple conditions

Python dictionary length of values

  • Let us see how to check the length of values in Python Dictionary.
  • In this example we can easily use list comprehension method to find the length of dictionary values.
  • We need to pass a object as an argument. The object may be an float, integer, etc

Example:

def main():
      
    my_dict = {'nu_list':[2, 5, 7],
           'nu_tupple':(9, 7, 6),
           'intg':9,
           'str_nu':"qwert",
           }
  
  
    no_count = sum([1 if isinstance(my_dict[x], (str, int))
                 else len(my_dict[x]) 
                 for x in my_dict])
      
    print("total length of values is:", no_count)
  

if __name__ == '__main__':
    main()

The output of the following given code.

Python dictionary length of values
Python dictionary length of values

Another example to check the length of values in the dictionary.

  • Here we can check how to find the length of values in the dictionary using dict.items() method.
  • This method returns the list and checks how many values are available in the dictionary. This method takes no parameters.

Example:

Let’s take an example and check how to find the length of values by using dict.items()

def main():
      
    my_dict = {'new_list':[9, 8, 9,7],
           'new_tupple':(4, 5, 6,8),
           'int_value':9,
           'new_str':"qwert"
           }
  
  
    cou_new = 0
  
   
    for ne_key, ne_val in my_dict.items():
          
     
        if isinstance(ne_val, int):
            cou_new += 1
  
    
        elif isinstance(ne_val, str):
            cou_new += 1
              
        else:
            cou_new += len(ne_val)
    print(" total length of value is:", cou_new)
if __name__ == '__main__':
    main()

The Screenshot of the implementation is given below.

Python dictionary length of values by dict.items
Python dictionary length of values by dict. items()

Read: Python Tkinter Quiz – Complete tutorial

Python dictionary length of keys

  • Let us see how to find the length of keys in the dictionary.
  • In this example,we can easily use the function len() to find the length of keys in a dictionary.
  • This function is used to return the number of iterable items available in an object. We can also use the keys() method to count the numbers using len().

Example:

Let’s take an example and check how to find the length of keys in the dictionary

dictionary = {'l':4,'m':8,'n':9}
b = len(dictionary.keys())
print("Length of keys",b)

Here is the execution of the following given code

Python dictionary length of keys
Python dictionary length of keys

How to find the length of keys in Python Dictionary

To calculate the number of keys in a Python dictionary we can easily use the function enumerate() and to return the number of iterable items available in an object.

Example:

my_dict = {'p':1,'r':2,'s':3,'t':7}

def New_key(dict):
    cou_no = 0
    for i in enumerate(dict):
        cou_no += 1
    return cou_no

print("Length of key",New_key(my_dict))

Here is the implementation of the following given code

Python dictionary length of keys by enumerator
Python dictionary length of keys by enumerator

This is how to check the length of keys in a dictionary.

Also read: Python dictionary initialize

Python dictionary list length

  • Let us see how to check the list of length in a dictionary.
  • In this example, we can easily use the function isinstance(). IsInstance() method takes two argument.A first argument is an object. We need to pass an object as an argument. The object may be a float, integer or string.

Example:

Let’s take an example and check how to find the list of lengths in a dictionary

def main():
      
    my_dict = {'new_list':[10, 11, 19,7,18],}
           
           
  
    cou_new = 0
    for ne_key, ne_val in my_dict.items():
          
     
        if isinstance(ne_val, int):
            cou_new += 1
  
    
        elif isinstance(ne_val, str):
            cou_new += 1
              
        else:
            cou_new += len(ne_val)
    print(" Dictionary list length:", cou_new)
if __name__ == '__main__':
    main()

Here is the output of the following given code

Python dictionary list length
Python dictionary list length

Read Python Dictionary Methods

Check the list of length in a dictionary

In this example, we can easily use the function len() to check the list of lengths in a dictionary in Python.

Example:

new_list = [3,4,7,8,9]
print("Length of list dictionary:",len(new_list))

The execution of the following code is given below.

Python list length len method
Python list length len() method

Read: Python dictionary filter

Python nested dictionary length

  • Here we can see how to find the length of a nested Python dictionary.
  • Nested dictionary is created as simple as we create a normal dictionary. The main difference is that each value is another dictionary.
  • In this example we can easily use the isinstance() method.

Example:

Let’s take an example and check how to find the length of a nested dictionary

my_dict ={
       'student_info':
           {
               'stu_name':'MIcheal',
               'L_name':'George'
           },
       'stu_Age':25,
       'stu_position':'Gamer',
       'stu_addr':
           {
           
           'stu_City':'Paris',
           'Country':'France'
           }       
      }
new_len = len(my_dict)

for x in my_dict.values():
      

    if isinstance(x, dict):
        new_len += len(x)
          
print("length of dictionary:", new_len) 

The implementation of the following code is given below.

Python nested dictionary length
Python nested dictionary length

Another example and check how to find the length of a nested dictionary

In this example, we can use the various tools that Python has to count the elements in this nested dictionary.

Example:

dict={'colours': 
         {'yellow': 'blue', 'pink': 'red', 'green': 'brown'}, 
       'Foods': 
         {'pasta': 'pizza', 'lamb': 'chicken', 'bread': 'butter'}}
b = len(dict)
c = len(dict['colours'])+len(dict['Foods'])
print("Nested dictionary length:",c)

The output of the following code is given below.

Python nested dictionary length method
Python nested dictionary length method

Python get length of empty dictionary

  • Here we can check how to get the length of the empty dictionary in Python.
  • By using the len() function to find out the length of this empty dictionary.
  • In this example, we will create an empty dictionary and count out the length of this dictionary.

Example:

Let’s take an example and check how to get the length of the empty dictionary

my_dict = {}

new_length = len(my_dict)

print('Length of empty dictionary:', new_length)

The execution of the given code is as follows.

Python get length of empty dictionary
Python get the length of an empty dictionary

Read: Python NumPy max with examples

Python dictionary string length

  • Let us see how to check the string length in a dictionary.
  • In this example we will check how many strings are present in the given dictionary by using isinstance() method.

Example:

def main():
      
    to_dict = {
           'str_nu':"qwertyuiop",'str2':"edddddwgf"
           }
  
  
    no_count = sum([1 if isinstance(to_dict[y], (str, int))
                 else len(to_dict[y]) 
                 for y in to_dict])
      
    print("total string length is:", no_count)
  

if __name__ == '__main__':
    main()

The output of the given code is as follows.

Python dictionary string length
Python dictionary string length

Another example to check how to count the string length in a dictionary

By using the len() function we can get the length of the given string. We can use the len() function to perform this particular task. This function helps the user to calculate the number of elements contains in the object.

Example:

Let’s take an example and check how to find the string length in a dictionary

my_dict = {'string1':"MIcheal",'string2':"JOhn",'string3':"George"}

print("Length of string in dictionary:",len(my_dict))

The implementation of the given code is as follows.

Python dictionary string length method
Python dictionary string length method

Python dictionary size limit

  • Here we can see how to get a size limit of dictionary.
  • For a string key in a dictionary it is the order of 1 microsecond. The timetaken increases moderately dependent on the number of elements present in the dictionary, possibly with something like a log value.
  • The performance slows down significantly for dictionaries larger than 2 raise to power 26 that is equal to 67,108,864. It takes 30 times longer to read from a dictionary.
  • In case if you significally choose the size 2 raise to power 27 that is equal to 134,217,728 and it is 9000 times longer to read from a dictionary but it depends on your system. It will not display the output because the computer ran out of memory before reaching 2^27. So there is no size limitation in the dictionary.

Python dictionary word length

To find the word length in the dictionary first insert it into the list and set. Now define a function that is word_length. The list of words corresponding to a key stores all the unique words from the text that have a length equal to the key value.

Example:

Let’s take an example and check how to find a word length in the dictionary.

from collections import defaultdict
def word_length(sentence):
    my_dict = defaultdict(set)

    for word in sentence.split():
        my_dict[len(word)].add(word)    

    return {key : list(value) for key, value in my_dict.items()}
sentence = "Python is a best programming language"
print(word_length(sentence))

The output of the given code is as follows.

Python dictionary word length
Python dictionary word length

Read: Python NumPy shape

Python dictionary key length performance

  • Let us see how to find the length of keys in the dictionary.
  • In this example,we can easily use the function len() to find the length of keys in a dictionary.

Example:

my_dict = {'p':5,'q':2,'r':1}
d = len(my_dict.keys())
print("Length of keys",d)

Here is the Screenshot of the following given code

Python dictionary key length performance
Python dictionary key length performance

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In this Python tutorial, we will discuss the Python dictionary length. Here we will also cover the below examples:

  • Python dictionary length of values
  • Python dictionary length of keys
  • Python dictionary list length
  • Python get length of empty dictionary
  • Python dictionary length limit
  • Python nested dictionary length
  • Python dictionary string length
  • Python dictionary size limit
  • Python dictionary word length
  • Python dictionary key length performance