Method # 1: Using vocabulary comprehension + startswith()
A combination of the above two methods can be used to accomplish this particular task. In this, startswith () dictionary comprehension does the main task of building the dictionary, and startswith () does the service task of checking keys starting with a specific prefix.
| # Python3 code to demonstrate how it works
# Key prefix matches in dictionary
# Using dictionary comprehension + startwith ()
# Initialize dictionary test_dict = { ’tough’ : 1 , ’to’ : 2 , ’do’ : 3 , ’todays’ : 4 , ’ work’ : 5 }
# print the original dictionary print ( "The original dictionary:" + str (test_dict))
# Initialize prefix test_pref = ’to’
# Using dictionary comprehension + startwith ()
# Key prefix matches in dictionary res = {key: val for key, val in test_dict.items () if key.startswith (test_pref)}
# print result print ( "Filtered dictionary keys are:" + str (res)) |
Output:
The original dictionary: {’to’: 2, ’tough’: 1, ’work’: 5, ’todays’: 4 , ’d o ’: 3}
Filtered dictionary keys are: {’ to ’: 2,’ tough ’: 1,’ todays’: 4}
Method # 2 : Using map () + filter () + items () + startswith ()
This particular task can also be accomplished using a combination of the above functions. The map function associates the startswith () filter logic with the elements of each dictionary retrieved by items()
| # Python3 code to demonstrate how it works
# Key prefix matches in the dictionary
# Using map () + filter () + elements () + start ()
# Initialize dictionary test_dict = { ’tough’ : 1 , ’to’ : 2 , ’ do’ : 3 , ’todays’ : 4 , ’work’ : 5 }
# print the original dictionary print ( "The original dictionary:" + str (test_dict))
# Initialize prefix test_pref = ’to’
# Using the map () + filter () + elements () + start ( )
# Key prefix matches in dictionary res = dict ( filter ( lambda item: item [ 0 ]. startswith (test_pref), test_dict. items ()))
# print result print ( "Filtered dictionary keys are:" + str (res)) |
Output:
The original dictionary: {’to’: 2, ’ tough ’: 1,’ work ’: 5,’ todays’: 4, ’do’: 3}
Filtered dictionary keys are: {’to’: 2, ’tough’: 1, ’todays’: 4}
