Python - Filter dictionary key based on the values in selective list

Sometimes in a Python dictionary we may need to to filter out certain keys of the dictionary based on certain criteria. In this article we will see how to filter out keys from Python dictionary.

With for and in

In this approach we put the values of the keys to be filtered in a list. Then iterate through each element of the list and check for its presence in the given dictionary. We create a resulting dictionary containing these values which are found in the dictionary.

Example

 Live Demo

dictA= {'Mon':'Phy','Tue':'chem','Wed':'Math','Thu':'Bio'}
key_list = ['Tue','Thu']

print("Given Dictionary:\n",dictA)
print("Keys for filter:\n",key_list)
res = [dictA[i] for i in key_list if i in dictA]

print("Dictionary with filtered keys:\n",res)

Output

Running the above code gives us the following result −

Given Dictionary:
   {'Mon': 'Phy', 'Tue': 'chem', 'Wed': 'Math', 'Thu': 'Bio'}
Keys for filter:
   ['Tue', 'Thu']
Dictionary with filtered keys:
   ['chem', 'Bio']

With intersection

We use intersection to find the common elements between the given dictionary and the list. Then apply the set function to get the distinct elements and convert the result to a list.

Example

 Live Demo

dictA= {'Mon':'Phy','Tue':'chem','Wed':'Math','Thu':'Bio'}
key_list = ['Tue','Thu']

print("Given Dictionary:\n",dictA)
print("Keys for filter:\n",key_list)

temp = list(set(key_list).intersection(dictA))

res = [dictA[i] for i in temp]

print("Dictionary with filtered keys:\n",res)

Output

Running the above code gives us the following result −

Given Dictionary:
   {'Mon': 'Phy', 'Tue': 'chem', 'Wed': 'Math', 'Thu': 'Bio'}
Keys for filter:
   ['Tue', 'Thu']
Dictionary with filtered keys:
   ['chem', 'Bio']

Pradeep Elance

Updated on 22-Jul-2020 08:34:33

• Related Questions & Answers
• Sort Dictionary key and values List in Python
• Convert key-values list to flat dictionary in Python
• Python - Filter dictionaries by values in Kth Key in list
• Python - Filter the negative values from given dictionary
• Python - Filter Rows Based on Column Values with query function in Pandas?
• Python – Inverse Dictionary Values List
• Python - Filter even values from a list
• Combining values from dictionary of list in Python
• Filter array based on another array in JavaScript
• Python – Extract Key’s Value, if Key Present in List and Dictionary
• Python program to get maximum of each key Dictionary List
• Python – Limit the values to keys in a Dictionary List
• Finding The Biggest Key In A Python Dictionary?
• Selective value selection in list of tuples in Python
• Filter an object based on an array JavaScript