iterating strings in python with for loop

Your code.

n = ["Michael", "Lieberman"] def join_strings(words): # words = ["Michael", "Lieberman"] result = "" for i in words: # i = 'Michael' for the first iteration. # if you do range(len(words)) then i=0 and words[0] is valid then result += words[i] #<--Error! i='Michael' and you can't do words['Michael'] return result print join_strings(n) 

Pythonic way of joining strings in the list:

print ''.join(n) #Outputs --> MichaelLieberman 

i is a string value not index. You can use enumerate function:

for index, i in enumerate(words): result += words[index] 

or you can just use the word itself:

for i in words: result += i 

Performance:

In [14]: timeit.timeit('string_cat', '''def string_cat(): ...: rg = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', ...: 't', 'u', 'v', 'w', 'x', 'y', 'z'] ...: st = '' ...: for x in rg: st += x ...: ''', number=1000000) Out[14]: 0.02700495719909668 In [15]: timeit.timeit('string_cat', '''def string_cat(): ...: rg = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', ...: 't', 'u', 'v', 'w', 'x', 'y', 'z'] ...: st = ''.join(rg) ...: ''', number=1000000) Out[15]: 0.026237964630126953 

if you r using for loop like :

for i in words: 

then do like this :

result += i 

because here we are taking values from list directly without mentioning any range or it's size.

if u r using for loop like :

for i in range(len(words)): 

then do like this :

result += words[i] 

and the output will be same from both the cases :

MichaelLieberman 

for better clarification about for loop refer this : https://www.learnpython.org/en/Loops