bebarrentine/codingpractice

Coding Practice

A repository of programming exercises. Yay!

Exercise One: Leap Year

In this exercise, you will need to use user inputs, a single for loop, and if/elif statements to make a program that can display which years a leap years within a given range. For example, if the user inputs the starting year 2000 and the ending year 2016 then it would print "2000 2004 2008 2012 2016".

Example Output:

Keep in mind, it's best to be able to prevent errors before they happen; therefore, have it set to where the program will only accept an integer for the user inputs.

As a bonus: If the user enters a letter, have the program prompt the user again until they enter an integer. This can be done in several different ways so get creative.

Solution Code

Here is just one way to accomplish this exercise

while True:

  try:
  #This asks the user for a starting year and ending year in order to 
  #calculate the amount of leap years between the two years
    startingYear = int(input("Enter the starting year: "))
    endingYear = int(input("Enter the ending year: "))
    print("\n")
  except ValueError:
    print("Sorry, that is not a valid year. Please try again\n")
    continue
  else:
    break

  #The following 'for' loop is what's used to determine and then display which
  #years between the start and end years are leap years
for leapYear in range (startingYear, endingYear + 1):
  #Follows the logic: if the year is divisible by 4 it is a leap year
  if leapYear % 4 == 0 and leapYear % 100 != 0:
    print(leapYear)
  #Follows the logic: if the year is divisible by 4, 100, and 400 it is a leap year
  elif leapYear % 4 == 0 and leapYear % 100 == 0 and leapYear % 400 == 0:
    print(leapYear)

Exercise Two: Drawing Diamonds

This exercise uses user input, for loops, if statements, and print statements to create the five stages of code to develop a complete diamond using asterisks and spaces. Keep in mind the user input must be an odd number.

Example Output:

As a bonus: Create an error statement to be printed if the user inputs an even number or invalid character. Have it set to prompt the user again for an answer or have the option to exit the code.

Solution Code

Here is just one way to accomplish this exercise

#prompts the user for a number to represent the variable diamondHeight
print("---------Stage 1---------")
diamondHeight = int(input("Enter the height of the diamond:"))

#This while loop prevents the user from inputting a number an even and/or negative number by displaying an error code and prompting them for a new number
while diamondHeight % 2 == 0 or diamondHeight <= 0:
  print("ERROR: The height must be an odd number greater than 0")
  diamondHeight = int(input("Please re-enter:"))  

#prints the statement when the height is a validated number
print("The validated height of the diamond is",diamondHeight,"\n")

print("---------Stage 2---------")
print('')
a = 1
for a in range(diamondHeight + 1):
  top = (diamondHeight - a)
  print ("* "*(a) + " "*top)
print('')

print("---------Stage 3---------")
print('')
a = 1
for a in range(diamondHeight + 1):
  if a%2 != 0:
    top = (diamondHeight - a)//2
    print ("* "*((a // 2) + 1))# + " "*top)
print('')


print("---------Stage 4---------")
print('')
a = 1
for a in range(diamondHeight + 1):
    if a%2 != 0:
        top = (diamondHeight - a) // 2
        print (" "*(top*2) + "* "*(a) + " "*(a-1) +" "*top)
print('')

print("---------Stage 5---------")
print('')
a = 1 #a placeholder variable used to solve the top half of the diamond
b = 1 #a placeholder variable used to solve the bottom half of the diamond

#This for loop produces the top half of the diamond by alternating astracts and spaces
for a in range(diamondHeight + 1):
    if a%2 != 0:
        top = (diamondHeight - a) // 2
        print (" "*top*2 + "* "*(a) + " "*top)

#This for loop produces the bottom half of the diamond by alternating astracts and spaces
for b in range(diamondHeight - 1,0,-1):
    if b%2 != 0:
        bot = (diamondHeight-b)//2
        print (" "*bot*2 + "* "*(b) + " "*bot)

Exercise Three: Currency Calculator

This exercise uses user input, if statements, functions, the split() method, and print statements to take an input of a cash value and then convert and print it into however many bills and coins are needed to equal the entered amount

Example Output:

As a bonus: Use while true to continue to run the program until a valid input is given. Try using try, except, and else

Solution Code

Here is just one way to accomplish this exercise

def main():

  print("Hello! Welcome to the currency calculator.\nEnter in a valid price (in decimal) and we'll tell you how much of each bill and coin you'll need to best meet that amount.\n")

  print ("Enter in a price:")

  #This while statements continues to run until a valid input is made (ie. integers that represent cash value) 
  while True:
    try:
      moneyAmount = float(input('> '))
    except:
      print("That wasn't a valid price!")
      continue
    else:
      break

  #converts the users input to a string to be split into dollars and cents
  moneyAmount = str(moneyAmount)

  #splitd the string on the decimal point
  billsSplit = moneyAmount.split('.')

  #assigns the seperate indexes of the splitted string to bills and cents
  bills = billsSplit[0]
  cents = billsSplit[1]

  #converts the string back to an integer
  bills = int(bills)
  cents = int(cents)

  #this function does the actual calculations of how many bills are needed
  def calcBills(bills):
    numHundreds = 0
    numFifties = 0
    numTwenties = 0
    numTens = 0
    numFives = 0
    numOnes = 0
    
    #calculates how many hundred dollar bills are needed and then subtract
    #from the original amount to solve for the rest of the bills (pattern
    #continues until it reaches one dollar bills)
    numHundreds = bills // 100
    bills = bills - numHundreds * 100
    
    numFifties = bills // 50
    bills = bills - numFifties * 50
    
    numTwenties = bills // 20
    bills = bills - numTwenties * 20
    
    numTens = bills // 10
    bills = bills - numTens * 10

    numFives = bills // 5
    bills = bills - numFives * 5
    
    numOnes = bills // 1
    bills = bills - numOnes

    #defines the variables within the displayBills function
    displayBills(numHundreds, numFifties, numTwenties, numTens, numFives, numOnes)

  #Uses calculations from calcBills to cleanly display bill amounts 
  def displayBills(numHundreds, numFifties, numTwenties, numTens, numFives, numOnes):
    print('')
    print("The paper bills you will need:\n")
    print(numHundreds,"Hundreds")
    print(numFifties, "Fifties")
    print(numTwenties, "Twenties")
    print(numTens, "Tens")
    print(numFives, "Fives")
    print(numOnes, "Ones\n")

  #this function does the actual calculations of how many coins are needed
  def calcCents(cents):
    numQuarters = 0
    numDimes = 0
    numNickels = 0
    numPennies = 0

    #calculates how many quarters are needed and then subtracts
    #from the original amount to solve for the rest of the coins (pattern
    #continues until it reaches pennies)
    numQuarters = cents // 25
    cents = cents - numQuarters * 25
    
    numDimes = cents // 10
    cents = cents - numDimes * 10

    numNickels = cents // 5
    cents = cents - numNickels * 5
    
    numPennies = cents // 1
    cents = cents - numPennies

    #defines the variables within the displayCents function
    displayCents(numQuarters, numDimes, numNickels, numPennies)

  #Uses calculations from calcBills to cleanly display coin amounts 
  def displayCents(numQuarters, numDimes, numNickels, numPennies):
    print("The coins you will need:\n")
    print(numQuarters, "Quarters")
    print(numDimes, "Dimes")
    print(numNickels, "Nickels")
    print(numPennies, "Pennies")

  #runs the functions to do the calculations
  calcBills(bills)
  calcCents(cents)

#runs code within main function
main()

Exercise Four: Most Popular Baby Name

This exercise uses user input, for loops, if statements, basic file methods, the split() method and print statements to open and search the user's specified file (names_1990s.txt, etc.) to display the inputted name's popularity rank. The program will ask the user for the name of the file and then open that file. It will also prompt the user for a full name and gender of the baby name. The program will then search the file for the first name in the appropriate column (one column for boys another for girls). If the name is found, the rank for that name will be printed to the screen.

Example Output:

As a bonus: Create an error statement to be printed if the user inputs a nonexistent file name. For an extra challenge, try to have a statement only print when the name is not found in the list unlike the constant statement as seen in the image.

Solution Code

Here is just one way to accomplish this exercise

def main():

  print ("What is your file name (with extension)?")
  fileName = input("> ")

  year = fileName.split('_')
  year = year[-1].split('.')
  year = year[0]

  try:
    txt = open(fileName,"r")

    print("\nEnter the baby's first and last name:")
    babyName = input("> ")
    babyName = babyName.split()
    babyName = babyName[0]

    print("\nEnter the gender of the baby (m/f)")
    babyGender = input("> ")

      
    for line in txt:
      if babyGender == "m":
        if line.split()[1] == babyName:
          print('\n',year,"Rank: ",line.split()[0])
        
      elif babyGender == "f":
        if line.split()[3] == babyName:
          print('\n',year,"Rank: ",line.split()[0])

      else:
        print("\nThe name was not ranked in that decade")

  except:
    print("This file does not exist")

main()

Exercise Five: Password Generator

Generate a password using strings and the join() method (hint: I recommend using either sample() or choice() methods depending how you want to go about it). The passwords should be random, generating a new password every time the user asks for a new password. Include your code in a main method. Be sure to type 'import random' at the top of your code

Example Output:

As a bonus: Instead of using a specified password length hard coded in, ask the user for the desired length. Ask the user how strong they want their password to be. For weak passwords, pick a word or two from a list.

Solution Code

Here is just one way to accomplish this exercise

import random

s = "abcdefghijklmnopqrstuvwxyz01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()?"
passlen = 8
p =  "".join(random.sample(s,passlen ))
print p

Exercise Six: Hangman

Recreate the game Hangman using the provided ASCII art. In this exercise, you should use lists, in operator, split(), lower(), upper(), startswith(), endswith(), and elif statements.

Example Output:

**Big photo~**

Solution Code

Here is just one way to accomplish this exercise

Solution: To Be Posted

Coming Soon: Text-Based Adventure and OOP Exercises

Python/IDE Resources

I'll add to this as time goes on

• Using Github in Pycharm - An article that gives instructions for using Github within Pycharm
• Stackoverflow - For all your questions and copy & paste needs
• Python Docs - The official python documentation, it's a beautiful thing