Practice Exercise 2 O Write a program that removes the nth index character from a nonempty string O Examples ==== RESTART: D:#2019 2 #45 (10A) #Week 3#2019xxxxxx_Week03.py Enter a nonempty string: Python Enter a index number: 1 New string: Pthon Enter a index number: 3 New string: Pyton Enter a index number: 5 New string: Pytho >>> 27 Practice Exercise 3 O Write a program to request a string O Count and display the number of vowels (a, e, i, o, u) in the sentence. ■ Program will not match lowercase or uppercase of the character. O Example ===== RESTART: D: W2019_2_#2019xxxxxx_Week03.py Enter a string: HELLO! My favorite program language is Python :) The number of vowel is: 14 >>> 28 Practice Exercise 4 O Write a program that creates a Caesar encryption Note: In cryptography, a Caesar cipher, also known as the shift cipher or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. Ex) with a left shift of 3, D would be replaced by A, E would become B, etc. We will use only lowercase characters with length of 3. We will not use "x", "y", "z" as an input O Examples ====== RESTART: D: W2019 2 BW2019xxxxxx_Week03.py Enter three characters: asf dvi >>> ===== RESTART: D:#2019_2_#2019xxxxxx_Week03.py Enter three characters: nrt quw >>> 29