Python Cheat Sheet

Addition

string + string	combine together
number +number	math - addition
string + number	crach

Data Types

String	a list of characters e.g. "abc123$%^", or empty string ""
Integer	whole numbers, and negative numbers e.g. -5, 0, 2, 99
Floating Point	decimal numbers e.g. 1.5, 2.0, -2.99
Boolean	True or False

True and False

True or anything is always True
False and anything is always False

Math

==	equal to
!=	no equal to
<	less than
>	v
<=	less than or equal to
>=	more than or equal to
%	Modulo, Find the remainder

Multiplication and Exponent

string * number	Combine that string
string* string	crash
number * number	Multiply (Math)
string ** string	CRASH!
number ** number	Exponent (Math)
string ** number	crash

Area of Circle

"""
Python Intro Assignment #2
name
student number
"""

#Ask the user for a radius of a circle
user_radius = input("What is a radius of a circle?")

#Convert the given radius to a floating point
radius = float(user_radius)

#Make a variable called pi
pi = float(3.1415)

#Calculate the area of the circle using exponents
area = pi(radius**2)

#Display the area of the circle to the user
print ("The area of the circle is", area)

Conditionals

If..... :then..... else.......	If the statement is true then do command under then else do command under else
while......	While this is true loop the command under the conditional
While True	loops forever
for each item in name of list	For every item in the list repeat the command under the loop that many times. (a string is a list too)

List

#what do you think will be the output of the following code: 

mastr = "hello123" # string is just a list of characters 
number = [1,2,3,4,5,6]
print (number)
shoppinglist = ['shoes','bags','pants','shirts])

#how to add an item at the end of the list 

shopping. append('ties')
print (shoppinglist)
for martin in shoppinglist
      print ('""' + martin + '""')

Add str

number1 = 1.0
number2 = 2.0

sum = str(number1) + str(number2)

print(sum)

Ans: 3.0

Define

def bacon ():
    print ("hello it's bacon")
    return
bacon()

Ans : hello it's bacon

def myprint(text):
    print ("" + str(text) + "")
    return
myprint(1)

Ans : 1

def myprintnew(text,decoration) :
    print(decoration + str(text) + decoration)
    return
myprintnew(1, "+++")
myprintnew(555, "+++")

Ans : +++1+++
+++555+++

def doubleIt (number) :
    return number * 2

print (doubleIt(5))

myvar = 12
myvar = doubleIt(myvar)
print (myvar)

Ans : 10, 24

def areaOfcircle(r):
    if r <= 0:
        return "error: invalid radius"
    pi = 3.1415
    area = pir*2
    return area

user_radius =input("Enter the radius: ")
r = float(user_radius)
print ('The area of the circle is', areaOfcircle(r))

mix the item

my str = "hello123"
numbers = [1,2,3,4,5,6]
print (numbers)

shoppinglist = ['shoes', 'bags', 'pants', 'shirts']
print (shoppinglist)

mixed = [1, 'hello', 2.5, True,False]
print (mixed)

Volume of prism

user_base = float(input("Enter the base of triangle: "))
user_height = float(input("Emter the hight of the triangle: "))
user_lenght = float(input("Enter the lenght of the triangle: "))

def volumeOfPrism (b,h,l):
    volume = 1/2  b  h * l
    return volume
print("The volume of the prism is",volumeOfPrism(user_base,user_height,user_lenght))

Function Largest Value

def max2(num1,num2):
    largestvalue = num1
    if num1 > num2:
        num1 = largestvalue
    else:
        largestvalue = num2
    return largestvalue



def max3 (num1,num2,num3):
    if num1>num2 and num1>num3:
        largestvalue = num1
    elif num2>num3 and num2>num1:
        largestvalue = num2
    else:
        largestvalue = num3 
    return largestvalue

print (max3(9,100,25))
print (max3(69,85,1))
print (max3(75,9,33))



def maxlist (list):
    largestvalue = list [0]
    for item in list:
       if item > largestvalue:
           largestvalue = item
    return largestvalue
mylist = [1,2,3,4,103,100,89,57]
print (maxlist(mylist))

Vocabulary

Variable	hold a value and can be changed
String	a list of characters such as number, letter, symbol
Integer	Whole number / counting number
Input	Gain information
Float number	The number in decimal
Syntax	Grammar/Structure of lauguage
Modulo	Find the remainder
Boolean	True/False
Function	define block of code that can reuse
Parameter	some thing you give to the function
Argument	some thing you give to the function
function call	Something that make the fuction work

Function

print()	Show information that you want on the screen
int()	Change number to be number integer
float()	Change number to be decimal number
input()	Gain information from user
str()	A list of number, letter and symbols
len()	The length of the string
#	Comment, no effect

Naming Convention

Rule for giving name
- letter
- numbers
- underscore _

Valid name
- _myStr
- my3
- Hello_there

Invalid name
- 3my=”hi” -- cannot start with number
- first name=”hi”
- first-name
- first+name

Sort word per line

mystr = "Hello" letter_num = 0 while letter_num < len(mystr): print (mystr[letter_num]) letter_num = letter_num + 1

H
e
l
l
o

Number to Hex

user_number = input("please enter a number: ")
number = int(user_number)
hex_string = ' '
while (number > 0):
    remaider = number % 16
    if remaider == 10:
        remaider = 'A'
    elif remaider == 11:
            remaider = 'B'
    elif remaider == 12:
            remaider = 'C'
    elif remaider == 13:
            remaider = 'D'
    elif remaider == 14:
            remaider = 'E'
    elif remaider == 15:
            remaider = 'F'
                            
    hex_string = str(remaider) + str(hex_string)
    number = number // 16
print ("Hexadecimal string is 0x", hex_string)

Random

import random
intlist = [1,2,3,4,5]
random_int = random.choice(intlist)
print (intlist,random_int)

fplist = [1.69,2.69,3.69,4.69,5.69]
random_fp = random.choice(fplist)
print (fplist,random_fp)

strlist = ['one','two','three','four','five']
random_str = random.choice(strlist)
print (strlist,random_str)

mylist = [1,1.69,'one']
random_item = random.choice(mylist)
print  (mylist,random_item)

myvar1 = 1
myvar2 = 2
myvar3 = 3
varlist = [myvar1,myvar2,myvar3]
random_var =random.choice(varlist)
print (varlist,random_var)

Palindrome

User_input = input("Type in an string: ")
reverse = ""
for letter in User_input:
    reverse = letter + reverse
print ("Reverse: ", reverse)
palindrome = reverse
if User_input == palindrome:
    print ("you input is palindrome")
else:
    print ("you input is not palindrome")

Palindrome 2

while True: 
    user_input = input("Enter the word: ")
    if user_input == "quit" :
       break
    print (len(user_input))
    reverse = ""
    for letter in user_input:
        reverse = letter + reverse
    palindrome = reverse
    if user_input == palindrome:
        print (user_input," is palindrome")
    else:
        print (user_input," is not palindrome")

Palindrome 3


def isPalindrome(word) :
    reverse = ""
    for letter in user_input:
        reverse = letter + reverse
    palindrome = reverse
    if palindrome:
        return True 
    else:
        return False
    
    
    
while True: 
    user_input = input("Enter the word: ")
    if user_input == "quit" :
       break
    print (len(user_input))

    ispal = isPalindrome(user_input)
    if ispal == True:
        print (user_input,"is a palindrome")
    else:
        print (user_input,"is not a palindrome")

Spelling a string out in reverse code

word = input("Type in an word: ")
reverse = ""
for letter in word:
    reverse = letter + reverse
print ("Reverse: ", reverse)

Area of triangle

user_base = float(input("Enter the base of triangle: "))
user_height = float(input("Emter the hight of the triangle: "))

def areaOfTriangle (b,h):
    area = 1/2  b  h
    return area
print ("The area of the triangle",areaOfTriangle(user_base,user_height))

Example

Print (2) – integer
Print (2.5) – floating point
Print (“Hello”) – string
Print (mystr) – variable
Print (mystr,”Hi”,2,1.0) -- commas

mystr = “Hi”
mystr ← name
“Hi” ← value can change

print (int(1.5)) → 1
print (int(“2”)) → 2
print (float(1)) → 1.0 anything to a float

Modulo/Remainder %
print (4%2) → 0
print (30%7) → 2

Print Name

name = "tim GIRARD"

print (name.upper()) → TIM GIRARD
print (name.lower()) → tim girard
print (name.capitalize()) → Tim girard
print (name.title()) → Tim Girard

Name strip

firstname = input("what is your first name? ")
lastname = input("what is your lastname? ")

fullname = firstname + " " + lastname

print("Your fullname is ") 
print (fullname)

letternumber = input("what is letter number? ")

mynumber = int(letternumber)-1

if (mynumber) > len(fullname):
    print ("invalid letter number, try again")
else:
    print (fullname[mynumber])

    repeat = input("how many times you want to print the letter? ")

    myrepeat = int(repeat)

    if (myrepeat) > 99:
        print ("too many letter! ")
    else:
        print(fullname[mynumber]*(myrepeat))

Reverse Word

while True:
          word = input("Please enter a word")
          index = 0
          reverse = ' '

          while int(index) < len(word):
                   reverse = word[index] + (reverse)
                   index = int(index) + 1

                   print ("Reverse: ", reverse)

Countdown Code

user_number = input("Please enter a number: ")

number = int(user_number)

countdown_string = ""

while number > 0:
    countdown_string = countdown_string + " " + str(number)
    number = number-1 

print (countdown_string)

This prints the true or false value using boolean

print(True)
print (2<3)
print (2 != 2)

Convert to binary

user_number = ' '

while user_number != ' 0 ' :
         user_number = input ("Enter a number to convert to binary")
         number = int(user_number)
         binary_string = ' '

        while (number > 0):
                 remainder = number%2
                 binary_string = str(remainder)+ binary_string
                 number = number//2

print ("Binary string is", binary_string)

Print definition

def printdefinition(word) :
    if word == "Variable" : 
        print ("""
        A variable is something that has volume. Also it can change 
        """)
    elif word == "Function" :
        print ("""
        A function is define block of code that can reuse
        """)
    elif word == "Paramiter" :
        print ("""
        A parameter and argument are some thing you give to the function
        """)
    elif word == "Function call" :
        print ("""
        A function call is something that make the fuction work 
        """)
    elif word == "String" :
        print ("""
        A string is a lis of characters
        """)

    else:
        print ("Unkonw word")
            
        
    return 


    
user_input = input("Enter the word")
printdefinition(user_input)

Guessing Game

"""
Group Members: Mind and Gam

Class: 10-05
"""
chance = 5
score = 0


mylist = ['coke','bacon', 'chicken', 'pocky', 'pepsi', 'pizza']

import random
random_item = random.choice(mylist)




while chance > 0:
    
    print ("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-")
    print ("Guessing Game")
    print ("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-")

    
    print ("Words:", mylist)
    



    user_guese = input("Guese the word: ")
    if user_guese == random_item:
        score = score+100
        print ("That's correct! Score:", score)
        random_item = random.choice(mylist)
    else:
        chance = chance-1
        if user_guese in mylist:
            print ("Sorry, wrong choice!")
            print ("Chances Remaining:", chance)
        else:
            print ("Sorry, that is not ever in the list")
            print ("Chances Remaining:", chance)

print ("Game Over! The word was", random_item)
print ("Final Score:", score)

For‐Loop with List:

forlist = [3, 4, 5, 2, 1]
for item in forlist:
 print(item)

While Loop with List

thelist = [4, 3, 2, 1, 0]
index = 0 # start at the first item
while index < len(thelist):
 print (thelist[index]) #prints each item
index = index + 1