Lab 4
Objectives:
- Practice with strings and loops
Palindrome detection
Write a function called is_palindrome that determines if a given string is a palindrome, i.e. is the same as its reverse. Here are some examples:
>>>is_palindrome('abba')
True
>>> is_palindrome('abab')
False
>>> is_palindrome('tenet')
True
>>> is_palindrome('banana')
False
>>> is_palindrome('straw warts')
True
True
>>> is_palindrome('abab')
False
>>> is_palindrome('tenet')
True
>>> is_palindrome('banana')
False
>>> is_palindrome('straw warts')
True
Substring counting
Write a function called count(s, substr) that returns how many times the string substr occurs in s. Here are some examples of the output your function should produce:
>>> count('is', 'Mississippi')
2
>>> count('an', 'banana')
2
>>> count('ana', 'banana')
2
>>> count('nana', 'banana')
1
>>> count('nanan', 'banana')
0
2
>>> count('an', 'banana')
2
>>> count('ana', 'banana')
2
>>> count('nana', 'banana')
1
>>> count('nanan', 'banana')
0
String reversal
Write a function called reverse that reverses a string. Here are some examples of the output your function should produce:
>>> reverse('happy')
'yppah'
>>> reverse('Python')
'nohtyP'
>>> reverse("")
''
>>> reverse("P")
'P'
'yppah'
>>> reverse('Python')
'nohtyP'
>>> reverse("")
''
>>> reverse("P")
'P'