Traversing a string

Traversing a string means visiting each character in turn, from the first to the last. There are two ways.

With a for loop: for ch in s: print(ch, end = ''). The loop goes from the first character to the last automatically, and stops by itself.

With a while loop, using an index:

• index = 0
• while index < len(s): print(s[index], end = ''); index += 1

The index runs from 0 to len(s) - 1; when it reaches len(s), the condition becomes false and the loop stops.

In both, end = '' keeps all the characters on one line, with nothing between them, instead of printing each on a new line.

Traversal is the basis of many string tasks: counting a character, searching for something, or building a new string character by character, as in the programs of section 8.6.