Chapter 3–5 Practice Problems#

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Set A: Strings#

1. Given s = "programming", what are the values of:

• s[0], s[-1], s[3], s[-3]
• s[0:4], s[4:], s[::-1]
• len(s), s * 2

1. Write code that takes a string s and creates a new string that is the first and last characters of s concatenated. For example, if s = "hello", the result is "ho".

1. What does "abc"[::-1] produce? What about "abcde"[4:0:-1]?

1. Write an expression that extracts every other character from a string s, starting from the first character.

Set B: Input and Output#

1. Write a program that asks for two numbers and prints their sum, difference, product, and quotient (to 2 decimal places). Use f-strings for output.

1. Write a program that asks for someone's first and last name separately, then prints: "Full name: LastName, FirstName".

1. Using format specifiers, print the number 3.14159265 in three ways:

• Rounded to 2 decimal places
• Rounded to 4 decimal places
• As a percentage (it's 314.159...%)

Set C: Branching#

1. Write a program that asks for a year and prints whether it's a leap year. A year is a leap year if:

• It's divisible by 4, AND
• It's not divisible by 100, UNLESS it's also divisible by 400. Examples: 2000 is a leap year, 1900 is not, 2024 is.

1. Write a program that:

• Asks the user to guess a secret number (hard-code the secret as 7)
• Tells them if their guess is too low, too high, or correct
• (We'll make this loop in Week 2)

1. Trace this code for each of x = 5, x = 10, x = 15:

    if x < 10:
        print("less")
    elif x == 10:
        print("equal")
    else:
        print("greater")

Set D: Challenge#

1. Write a program that asks for three numbers and prints them in sorted order (smallest to largest) without using Python's built-in sorted() or sort() functions. Use only comparisons and if/elif/else.

1. Write a program that asks the user for a word and prints:

• The word reversed
• Whether the word is a palindrome (reads the same forwards and backwards)
• The word with the first and last characters swapped