Python Python String Manipulation and Formatting 2

Question 1

How do you check if a string starts with a specific prefix in Python?

Accepted Answer

str.startswith('py')

Answer

startswith() returns True if the string begins with the specified prefix.

Question 2

What is the result of `''.join(['a','b','c'])`?

Accepted Answer

'abc'

Answer

join() concatenates list elements using the calling string as separator; an empty string means no separator.

Question 3

What does `'Python'[1:4]` evaluate to?

Accepted Answer

'yth'

Answer

Slicing [1:4] returns characters at indices 1, 2, and 3, which are 'y', 't', 'h' → 'yth'.

Question 4

Which method returns the index of the first occurrence of a substring, or -1 if not found?

Accepted Answer

find()

Answer

find() returns the lowest index where the substring is found, or -1 if absent; index() raises ValueError instead.

Question 5

What does the format string `'{0} {1}'.format('Hello', 'World')` produce?

Accepted Answer

'Hello World'

Answer

Positional placeholders {0} and {1} are replaced with the first and second format arguments.

Python Practice Test