How to double the strings in Python ex. "Hello" to "HHeelllloo"

Question

how do I do this with sliced notation?

ex. "Hello" to "HHeelloo"

Answer 1

The term slicing in programming usually refers to obtaining a substring, sub-tuple, or sublist from a string, tuple, or list respectively. You cannot slice a string to double every character. Though you can use sliced notation- method 6. Here are some methods to get the desirable output.

Method 1:

input = Hello
output=""
for i in input:
    output = output + i*2
print(output)  

Method 2:

"".join(2 * i for i in "Hello")

Method 3:

s='Hello'
from itertools import chain,izip
''.join(chain(*izip(s,s)))

Method 4:

s.translate({ord(x):2*x for x in set(s)})

Method 5:

s = "Hello"
import re
re.sub('(.)', r'\1' * 2, s)

Method 6 (using sliced notation):

s = "Hello"
s1 = 2 * s
s2 = ""
for i in range(len(s)):
    s2 += s1[i::len(s)]
print(s2)

All would result in:

HHeelllloo