Method # 1: Using a loop
This is a crude method in which this task can be accomplished. In this we loop over the list of indices and concatenate the corresponding index characters from the string.
| # Python3 code to demonstrate how it works
# Get positional characters from a string
# using a loop
# initialization string test_str = " gfgisbest "
# print the original line print ( " The original string is: " + test_str)
# initializing the index list indx_list = [ 1 , 3 , 4 , 5 , 7 ]
# Get positional characters from a string
# using a loop res = ’’ for ele in indx_list: res = res + test_str [ele]
# print result print ( "Substring of selective characters:" + res) |
Output:
The original string is: gfgisbest Substring of selective characters: fisbs
Method # 2: Using a generator expression + enumerate()
A combination of the above functions can be used to accomplish this task ... In this, we start a loop using a generator expression and retrieve the indices using enumerate ().
| # Python3 code to demonstrate how it works
# Get positional characters from string
# using generator expression + enumerate ()
# initialization string test_str = "gfgisbest"
# print the original line print ( "The original string is:" + test_str)
# initializing the index list indx_list = [ 1 , 3 , 4 , 5 , 7 ]
# Get positional characters from a string
# using generator expression + enumerate () res = ’’ .join ((char for idx, char in enumerate (test_str) if idx in indx_list))
# print result print ( "Substring of selective characters:" + res) |
Exit:
The original string is: gfgisbest Substring of selective characters: fisbs
