First Python Project

I'm attempting the first project from a book I'm trying to learn Python from.

The task was to write a function called 'collatz', with a parameter named 'number'.   if number is even, then collatz should print number // 2 and return this value.

If odd then collatz should print and return 3 * number + 1.

Then the task was to write a program that lets the user input an integer, so that collatz keeps getting called with the entered argument, until the return value is 1.

I know I've printed in the loop, rather than the function, but other than that, does it seem ok?

# The Collatz Sequence

def collatz(number):
    if number % 2 == 0:
        return (number // 2)
    elif number % 2 == 1:
        return (3 * number + 1)

ans = ''


while ans != 1:
    print('Enter an integer')
    r = int(input())
    ans = collatz®
    print(ans)
 

There was a bit more to the task.  Use Try and Except to check that an integer is being entered.  Changed variable r to o as was appearing strange when posted.

# The Collatz Sequence

def collatz(number):
    if number % 2 == 0:
        return (number // 2)
    elif number % 2 == 1:
        return (3 * number + 1)

ans = ''


while ans != 1:
    print('Enter an integer')
    try:
        o = int(input())
    except ValueError:
        print('That is not an integer, try again!')
        continue

    ans = collatz(o)
    print(ans)

ans = "" not ans = "

ans = "" not ans = "

That's two single quotes.  The book I'm learning from says to use single quotes.  Thanks for the reply. 

On to project 2:  Write a function that takes a list value as an argument, and returns a string with all the items separated by a comma and a space, with and inserted before the last item.  The function should be able to work with any list value passed to it.

Is this OK?

# Comma Code Project

def commaCode(meow):
    global biggerCats
    for i in range(len(meow)):
        if i < len(meow) - 1:
            biggerCats = biggerCats + (meow[i] + ', ')
        elif i == len(meow) - 1:
            biggerCats = biggerCats + ('and ' + meow[len(meow) - 1])                          
        else:
            return biggerCats
            

                            


biggerCats = ''

cats = []

while True:
        print('Enter name of cat ' + str(len(cats) + 1) + ', or enter nothing to finish.')
        name = input()
        if name == '':
            break
        cats.append(name)

commaCode(cats)

print(biggerCats)

Don't make biggerCats global. Have you ever checked what happens if you use your commaCode function twice in your script? It will append the string of the second list to the string for the first list, which is not a behaviour you would expect or want.

Thanks for the reply.  I am aware of the basic differences between the global scope and local scopes, but the task seemed to indicate the function only had to work once.

Good advice for the future though.  Thanks. 

I've done it without the global variable in the function.

# Comma Code Project

def commaCode(meow):
    biggerCats = ''
    for i in range(len(meow)):
        if i < (len(meow) - 1):
            biggerCats = biggerCats + (meow[i] + ', ')
        elif i == len(meow) - 1:
            biggerCats = biggerCats + ('and ' + meow[len(meow) - 1])                          
    return biggerCats

            

                            


cats = []

while True:
        print('Enter name of cat ' + str(len(cats) + 1) + ', or enter nothing to finish.')
        name = input()
        if name == '':
            break
        cats.append(name)

answerCats = commaCode(cats)

print(answerCats)

Edited by thelittleduck, 30 March 2016 - 11:09 PM.

The task this time was to make a given nested list, print as a ceratin image - from left 90 degrees clockwise.

Is this OK?

# Character Picture Grid


grid = [['.', '.', '.', '.', '.', '.'],
        ['.', '0', '0', '.', '.', '.'],
        ['0', '0', '0', '0', '.', '.'],
        ['0', '0', '0', '0', '0', '.'],
        ['.', '0', '0', '0', '0', '0'],
        ['0', '0', '0', '0', '0', '.'],
        ['0', '0', '0', '0', '.', '.'],
        ['.', '0', '0', '.', '.', '.'],
        ['.', '.', '.', '.', '.', '.']]


        
for x in range(6):
    for y in range(9):
        if y != 8:
            print(grid[y][x], end ='')
        else:
            print(grid[y][x])

The next project was to write a function that adds a list of found items, to a dictionary of already owned items.  Also to write a function that calculates the total objects owned.

Does this seem OK?

# List to Dictionary Function for Fantasy Game Inventory


playerHas = {'Gold': 82, 'Food': 5, 'Drink': 4, 'Magic': 45, 'Sword': 2}



def addToInventory(inventory, addItems):
    for i in addItems:
        inventory.setdefault(i, 0)
        inventory[i] = inventory[i] + 1

    
def displayInventory(inventory):
    print('Inventory:')
    itemTotal = 0
    for k, v in inventory.items():
        print(str(v) + ' ' + k)
        itemTotal = itemTotal + v
    print('Total number of items: ' + str(itemTotal))




dragonLoot = ['Gold', 'Food', 'Gold', 'Magic', 'Axe', 'Gold', 'Magic', 'Drink', 'Gold', 'Sword']


addToInventory(playerHas, dragonLoot)


displayInventory(playerHas)

This time the project was to write  a function that takes a list of strings, and displays it in a well-organized table with each column right-justified.

It said to assume the inner lists will contain the same number of strings.  Does this seem acceptable?

# Table Printer


stuff = [['Vodka', 'Whiskey', 'Cider', 'Beer', 'Wine'],
         ['Nuts', 'Cheese', 'Biscuits', 'Crisps', 'Dip'],
         ['DVD', 'Book', 'TV', 'Cinema', 'Match']]



def tablePrinter(tableData):
    colWidths = [0] * len(tableData)
    for i in range(len(tableData)):
        for x in tableData[i]:
            if len(x) > colWidths[i]:
                   colWidths[i] = len(x)

    glue = []
    size = 0
    for y in range(len(tableData[size])):
                   for z in range(len(tableData)):
                       glue.append(tableData[z][y])
                       continue
                   for a in range(len(tableData) - 1):
                       print(glue[a].rjust(colWidths[a]) + ' ', end = '')
                       continue
                   print(glue[len(tableData) - 1].rjust(colWidths[len(tableData) -1]))
                   glue = []
                   size = size + 1

tablePrinter(stuff)

Edited by thelittleduck, 19 April 2016 - 01:18 PM.

This time the task was to write a function that uses regular expressions, to check that a password is strong.

The authors definition of a strong password - at least 8 characters long, with both uppercase and lowercase letters, and at least one digit.  It said several regexes would need to be used.

Does this seem OK?

# Strong Password Regex

import re

checkRegexLen = re.compile(r'(.){8,}')
checkRegexUpper = re.compile(r'[A-Z]+')
checkRegexLower = re.compile(r'[a-z]+')
checkRegexDigit = re.compile(r'\d+')


def strongPC(check):
    if checkRegexLen.search(check) == None:
        return 'Password must be at least 8 characters.'
    if checkRegexUpper.search(check) == None:
        return 'Password must contain at least one uppercase letter.'
    if checkRegexLower.search(check) == None:
        return 'Password must contain at least one lowercase letter.'
    if checkRegexDigit.search(check) == None:
        return 'Password must contain at least one digit.'
    return 'Password accepted.'


while True:
    print('Enter password.')
    password = input()
    ans = strongPC(password)
    if not ans == 'Password accepted.':
        print(ans)
        continue
    print(ans)
    break

Thought I would try to convert positive integers from decimal to octal.

This is what I ended with:

# decimal to octal converter

print('What number do you want to convert? ')

while True:
    decimal = input()
    if decimal.isdecimal():
        break
    print('Invalid input')
    print()
    continue

swap = int(decimal)
answerstring = []
trail = 5

while not trail == 0:
    answerstring.append(swap % 8)
    trail = swap // 8
    swap = trail
    continue
    
print(answerstring)
print('The answer is...')
print()
l = (len(answerstring) - 1)

for i in range(l, -1, -1):
    print(answerstring[i], end='')

Edited by thelittleduck, 03 March 2017 - 08:48 PM.

I tried doing a tic-tac-toe game. Here's what I ended up with.

# Tic Tac Toe

import random, sys, time

def showPoss():
    print('Keys')
    print()
    print('t-l t-c t-r')
    print()
    print('m-l m-c m-r')
    print()
    print('b-l b-c b-r')
    print()
   
def humanWins():
    print()
    print('Congratulations!  You have won!')
    time.sleep(3)
    sys.exit()

def computerWins():
    print()
    print('The computer has won')
    time.sleep(3)
    sys.exit()

def checkWin(spacing, play):
    if (spacing['t-l'] + spacing['t-c'] + spacing['t-r'] == 'XXX' or
        spacing['m-l'] + spacing['m-c'] + spacing['m-r'] == 'XXX' or
        spacing['b-l'] + spacing['b-c'] + spacing['b-r'] == 'XXX' or
        spacing['t-l'] + spacing['m-l'] + spacing['b-l'] == 'XXX' or
        spacing['t-c'] + spacing['m-c'] + spacing['b-c'] == 'XXX' or
        spacing['t-r'] + spacing['m-r'] + spacing['b-r'] == 'XXX' or
        spacing['t-l'] + spacing['m-c'] + spacing['b-r'] == 'XXX' or
        spacing['b-l'] + spacing['m-c'] + spacing['t-r'] == 'XXX'):       
        if play == 1:
            humanWins()
        else:
            computerWins()
    if (spacing['t-l'] + spacing['t-c'] + spacing['t-r'] == 'OOO' or
        spacing['m-l'] + spacing['m-c'] + spacing['m-r'] == 'OOO' or
        spacing['b-l'] + spacing['b-c'] + spacing['b-r'] == 'OOO' or
        spacing['t-l'] + spacing['m-l'] + spacing['b-l'] == 'OOO' or
        spacing['t-c'] + spacing['m-c'] + spacing['b-c'] == 'OOO' or
        spacing['t-r'] + spacing['m-r'] + spacing['b-r'] == 'OOO' or
        spacing['t-l'] + spacing['m-c'] + spacing['b-r'] == 'OOO' or
        spacing['b-l'] + spacing['m-c'] + spacing['t-r'] == 'OOO'):
        if play == 1:
            computerWins()
        else:
            humanWins()
   
def compMove2(goes, spa, a):
    if a < 3:
        if spa['m-c'] == ' ':
            spa['m-c'] = goes
        else:
            spa['t-l'] = goes
        return
    if a == 3:
        if spa['t-l'] == ' ':
            spa['t-l'] = goes
        elif spa['b-l'] == ' ':
            spa['b-l'] = goes
        else:
            spa['b-r'] = goes
        return            
    if spa['b-l'] == ' ':
        spa['b-l'] = goes
    elif spa['b-r'] == ' ':
        spa['b-r'] = goes
    else:
        spa['t-r'] = goes
                      
def compMove(go, spac, compsGo):
    while True:
        move = random.randint(0, 8)
        if not spac[compsGo[move]] == ' ':
            continue
        spac[compsGo[move]] = go
        return
         
def checkMove(moves, space, compsGo):
    again = 0
    for i in range(9):
        if not compsGo[i] == moves:
            again += 1
        if again == 9:
            return 'takens'
        
    if not space[moves] == ' ':
        return 'taken'
        
def showBoard(space, playing):
    print('   |   |    ')
    print(' ' + space['t-l'] + ' | ' + space['t-c'] + ' | ' + space['t-r'])
    print('___|___|___')
    print('   |   |    ')
    print(' ' + space['m-l'] + ' | ' + space['m-c'] + ' | ' + space['m-r'])
    print('   |   |    ')
    print(u'̅̅̅|̅̅̅|̅̅̅')
    print(' ' + space['b-l'] + ' | ' + space['b-c'] + ' | ' + space['b-r'])
    print('   |   |    ')
    time.sleep(0.7)

    checkWin(space, playing)

spaces = {'t-l': ' ', 't-c': ' ', 't-r': ' ',
          'm-l': ' ', 'm-c': ' ', 'm-r': ' ',
          'b-l': ' ', 'b-c': ' ', 'b-r': ' '}

compGo = ['t-l', 't-c', 't-r',
          'm-l', 'm-c', 'm-r',
          'b-l', 'b-c', 'b-r']

while True:
    print()
    print('Choose level 1-2 (2 is hardest)')
    print()
    level = input()
    if level.isdecimal():
        if int(level) < 1 or int(level) > 2:
            print('Out of range')
            continue
        else:
            level = int(level)
            break
    else:
        print('Enter a number please')
    
while True:
    print('Enter 1 to be X or 2 to be O (X goes first)')
    print()
    choice = input()
    if choice == '1':
        turn, player, cg = 'X', 1, 'O'
        break
    if choice == '2':
        turn, player, cg = 'O', 2, 'X'
        break
    print('Invalid choice. Please choose again')
    print()

showPoss()

for i in range(1, 10):
    print()
    if (player == 1 and (i % 2 == 1) or player == 2 and (i % 2 == 0)):
        while True:
            print('Please enter your move')
            print()
            move = input()
            isTaken = checkMove(move, spaces, compGo)
            if isTaken == 'takens':
                print('Invalid move')
                print()
                continue
            if isTaken == 'taken':
                print('That space is already taken, please enter another move')
                print()
                continue
            if player == 1:
                spaces[move] = 'X'
            else:
                spaces[move] = 'O'
            showBoard(spaces, player)
            break
    if (player == 1 and(i % 2 == 0) or player == 2 and (i % 2 == 1)):
        if level == 1:
            compMove(cg, spaces, compGo)
        if level == 2 and i > 4:
            compMove(cg, spaces, compGo)
        if level == 2 and i < 5:
            compMove2(cg, spaces, i)
        showBoard(spaces, player)
           
print()
print('It\'s a draw!')
time.sleep(3)
 

I'd recommend putting this on github.  It makes it easier to categorise and share your projects and others can give you feedback!