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  2. Python | Lead and Trail String List Placeholder

Python | Lead and Trail String List Placeholder



Method # 1: Using List Comprehension

This task can be accomplished using List Comprehension. In this, we iterate over each inline element and restore a new list of lines after adding the required line to the back and front of each line.

# Python3 demo code
# Trail and leading list of strings
# using comprehension list

 
# initialize the list

test_list = [ "a" , "b" , "c" ]

 
# print the original list

print ( "The original list:" + str (test_list))

 
# initialize pad_str

pad_str = `gfg`

  
# Trail and leading list of strings
# using comprehension list

res = [pad_str + ele + pad_str  for ele in test_list]

  # print result

print ( "The String list after padding:" + str (res))

Output: 

 The original list: [`a`,` b`, `c`] The String list after padding: [` gfgagfg`, `gfgbgfg`,` gfgcgfg`]

Method # 2: Using comprehension list + string formatting

This task can also be accomplished using a combination of the above functions. In this we accomplish the padding task using a formatted string than the + operator.

# Python3 code to demonstrate how it works
# Trail and leading list of lines
# use comprehension list + line formatting

  
# initialize the list

test_list = [ "a" , "b" , "c" ]

  
# print original list

print ( "The original list:" + str (test_list))

 
# initialize pad_str

pad_str = `gfg`

 
# Trail and leading list of lines
# using comprehension list + string formatting

temp = pad_str + ` {0} ` + pad_str

res =   [temp. format (ele) for ele in test_list]

 
# print result

print ( "The String list after padding:" + str (res))

Output: 

 The original list: [`a`,` b`, `c`] The String list after padding: [` gfgagfg` , `gfgbgfg`,` gfgcgfg`]