Python Practice Problems

Python practice problems help beginners to become experts in a python programming language with a small amount of practice effort.

Python program to get the sum of unique elements from dictionary list values.

by

In this python dictionary program, we will get the sum of unique elements from dictionary list values.

Steps to solve the program
  1. Take a dictionary with the value list as input and create an empty list.
  2. Use for loop to iterate over the value list of the dictionary.
  3. Add unique elements from the value list to the empty list using a nested for loop and an if statement.
  4. Get the sum of the list using sum().
  5. Print the output.
				
					D1 = {'a':[6,7,2,8,1],'b':[2,3,1,6,8,10],'d':[1,8,2,6,9]}
l = []

for v in D1.values():
    for num in v:
        if num not in l:
            l.append(num)
            
print("Sum: ",sum(l))

Output :

				
					Sum:  46
Previous

reverse each string value in the dictionary and add an underscore before and after the Keys.

Reverse string value in the dictionary and add an underscore before and after the Keys.

by

In this python dictionary program, we will reverse string value in the dictionary and add an underscore before and after the Keys.

Steps to solve the program
  1. Take a dictionary with string values as input and create an empty dictionary.
  2. Use for loop to iterate over keys and values of the dictionary.
  3. Add an underscore before and after the key using string concatenation.
  4. Add that key to the empty dictionary and its value also.
  5. Print the output.
				
					D1 = {'a':'Python','b':'Programming','c':'Learning'}
D2 = {}

for k,v in D1.items():
    D2['_'+k+'_'] = v[::-1]
    
print(D2)

Output :

				
					{'_a_': 'nohtyP', '_b_': 'gnimmargorP', '_c_': 'gninraeL'}
Next

sum unique elements from dictionary list values.

Python program to invert a dictionary with non-unique hashable values.

by

In this python dictionary program, we will invert a dictionary with non-unique hashable values.

Steps to solve the program
  1. Take a dictionary as input.
  2. From collections import defaultdict. (The Python defaultdict type behaves almost exactly like a regular Python dictionary, but if you try to access or modify a missing key, then defaultdict will automatically create the key and generate a default value for it)
  3. Take a variable and assign its value equal to defaultdict(list).
  4. Use for loop to iterate over keys and values of the input dictionary.
  5. Add the same values with the different keys as keys and their keys as values to that variable to that variable.
  6. Print the output.
				
					from collections import defaultdict
D1 = {'alex':1,'bob':2,'martin':1,'robert':2}
obj = defaultdict(list)

for key, value in D1.items():
    obj[value].append(key)
    
print(obj)

Output :

				
					defaultdict(<class 'list'>, {1: ['alex', 'martin'], 2: ['bob', 'robert']})
Previous

rename key of a dictionary

Next

Sort Dictionary by values summation

Python program to rename key of a dictionary

by

In this python dictionary program, we will rename key of a dictionary

Steps to solve the program
  1. Take a dictionary as input.
  2. Add a new key and assign its value to the previous key using pop().
  3. In this way, we will rename the key for that value.
  4. Print the output.
				
					D1 = {'a':19,'b': 20,'c':21,'d':20}
D1['e'] = D1.pop('d')
        
print(D1)

Output :

				
					{'a': 19, 'b': 20, 'c': 21, 'e': 20}
Previous

delete a list of keys from a dictionary.

Next

Invert a given dictionary with non-unique hashable values.

Python program to delete a list of keys from a dictionary.

by

In this python dictionary program, we will delete a list of keys from a dictionary.

Steps to solve the program
  1. Take a dictionary and a list of keys as input.
  2. Use for loop to iterate over keys in the list.
  3. Delete the keys from the diction using del.
  4. Print the output.
				
					D1 = {'a':19,'b': 20,'c':21,'d':20,'e':50}
Key = ['a','d','e']

for key in Key:
    del D1[key]
    
print(D1)

Output :

				
					{'b': 20, 'c': 21}
Previous

initialize a dictionary with default values.

Next

rename key of a dictionary

Python program to initialize a dictionary with default values

by

In this python dictionary program, we will Initialize a dictionary with default values

Steps to solve the program
  1. Take a list of keys as input and create a dictionary to set the default values for those keys.
  2. Create an empty list.
  3. Use for loop to iterate over keys in the list and add those keys to the empty dictionary and set up their values as default values using another dictionary that we have created.
				
					Name = ['Virat','Rohit']
Defaults = {'sport':'cricket','salary':100000}
D1 = {}

for name in Name:
    D1[name] = Defaults
    
print(D1)

Output :

				
					{'Virat': {'sport': 'cricket', 'salary': 100000}, 'Rohit': {'sport': 'cricket', 'salary': 100000}}
Previous

create a flat list of all the values in a flat dictionary. 

Next

delete a list of keys from a dictionary.

Create a list of all the values in a dictionary. 

by

In this python dictionary, we will create a flat list of all the values in a flat dictionary. 

Steps to solve the program
  1. Take a dictionary as input and create an empty list.
  2. Use for loop to iterate over values of the dictionary.
  3. Add the values to the list using the append() function.
  4. Print the output.
				
					D1 = {'sqa':1,'tools':2,'is':3,'best':4} 
l = []

for k in D1.values():
    l.append(k)
    
print(l)

Output :

				
					[1, 2, 3, 4]
Previous

create a flat list of all the keys in a flat dictionary.

Next

initialize a dictionary with default values

Create a list of all the keys in a dictionary.

by

In this python dictionary program, we will create a flat list of all the keys in a flat dictionary.

Steps to solve the program
  1. Take a dictionary as input and create an empty list.
  2. Use for loop to iterate over keys of the dictionary.
  3. Add the keys to the list using the append() function.
  4. Print the output.
				
					D1 = {'sqa':[1,2,5,6],'tools':[3,8,9],'is':[2,5,0],'best':[3,6,8]} 
l = []

for k in D1.keys():
    l.append(k)
    
print(l)

Output :

				
					['sqa', 'tools', 'is', 'best']
Previous

convert given a dictionary to a list of tuples.

Next

create a flat list of all the values in a flat dictionary. 

Convert given a dictionary to a list of tuples.

by

In this python dictionary program, we will convert given a dictionary to a list of tuples.

Steps to solve the program
  1. Take a dictionary as input.
  2. Convert the dictionary to a list of tuples using list() and items().
  3. Print the output.
				
					D1 = {'a':19,'b':20,'c':21,'d':20}
l = list(D1.items())
    
print(l)

Output :

				
					[('a', 19), ('b', 20), ('c', 21), ('d', 20)]
Previous

find all keys in the provided dictionary that have the given value.

Next

create a flat list of all the keys in a flat dictionary.

Find all keys in the provided dictionary that have the given value.

by

In this python dictionary program, we will find all keys in the provided dictionary that have the given value.

Steps to solve the program
  1. Take a dictionary as input and create an empty list.
  2. Use for loop to iterate over keys and values of the dictionary.
  3. If a value is equal to 0 then add its key to the list using append().
  4. Print the output.
				
					D1 = {'a':19,'b':20,'c':21,'d':20}
l = []

for k,v in D1.items():
    if v == 20:
        l.append(k)
        
print(l)

Output :

				
					['b', 'd']
Previous

convert a list of dictionaries into a list of values corresponding to the specified key.

Next

convert given a dictionary to a list of tuples.