Where is mistake?

Question

Where is mistake?

a=str(input())
n=len(a)
for i in range (n):
if a[i] ==1:
a[i]="one"
if a[i]==2:
a[i]="two"
if a[i]==3:
a[i]="three"
if a[i]==4:
a[i]="four"
if a[i]==5:
a[i]="five"
if a[i]==6:
a[i]="six"
if a[i]==7:
a[i]="seven"
if a[i]==8:
a[i]="eight"
if a[i]==9:
a[i]="nine"
if a[i]==10:
a[i]="ten"
if a[i]==0:
a[i]="zero"

print (a)

input: 1 is the loneliest number
output: 1 is the loneliest number

there should be "one is the loneliest number"

Answer 1

a is a string. So a[i] can only be equal to '1', '2'..... and not 1, 2.......
i.e. a[i] cannot be an integer, so compare it with a string.

Answer 2

Also even after you correct that, the program is going to cause an error as you cannot change an index of a string.

Instead of a[i] = "one", do
a = a.replace(" 1", "one")
for all the digits

Answer 3

thank you!!