Python | Get specific keys' values

Sometimes, we require all the values, but many times, we have specified keys of whose value list we require. This is quite common problem for web development. Let’s discuss certain ways in which this problem can be solved.

Method #1 : Using list comprehension
This task can be performed using list comprehension adopted as the shorter way to perform the longer task of checking using loop. This offers a one liner approach to solve this problem.

# Python3 code to demonstrate working of 
# Get specific keys' values 
# Using list comprehension 
  
# initializing dictionary 
test_dict = {'gfg' : 1, 'is' : 2, 'best' : 3} 
  
# initializing keys 
filt_keys = ['gfg', 'best'] 
  
# printing original dictionary 
print("The original dictionary is : " + str(test_dict)) 
  
# Extract specific value list from dictionary 
# Using list comprehension 
res = [test_dict[key] for key in filt_keys] 
  
# printing result 
print("Filtered value list is : " +  str(res)) 

Output :

The original dictionary is : {'is': 2, 'best': 3, 'gfg': 1}
Filtered value list is : [1, 3]

Method #2 : Using map() + get()
The combination of above functions can offer a more compact solution for this task. The map function can be used to extend the logic to whole dictionary and get function is used to fetch key’s value.

# Python3 code to demonstrate working of 
# Get specific keys' values 
# Using map() + get() 
  
# initializing dictionary 
test_dict = {'gfg' : 1, 'is' : 2, 'best' : 3} 
  
# initializing keys 
filt_keys = ['gfg', 'best'] 
  
# printing original dictionary 
print("The original dictionary is : " + str(test_dict)) 
  
# Extract specific value list from dictionary 
# Using map() + get() 
res = list(map(test_dict.get, filt_keys)) 
  
# printing result 
print("Filtered value list is : " +  str(res)) 

Output :

The original dictionary is : {'is': 2, 'best': 3, 'gfg': 1}
Filtered value list is : [1, 3]

My Personal Notes

Python | Get specific keys’ values

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