Show Menu
Cheatography

python cheat sheet - ToeyD Cheat Sheet by

Vocabulary

Variable
Hold a value and be change
String
A list of character such as number, letter and symbols
Integer number
Whole number­/co­unting number
Float number
The number in decimal
Syntax
Gramma­r/S­tru­cture of language
Modulo
Find the remainder
Boolean
True/False

Function

print()
Show the 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

Forever While Loop

while True: # forever
    user_input = input('Enter a number: ')
    number = int(user_input)
    print ('The number squared is', number ** 2)

Condit­ional While Loop

count = 0 # start at zero
while count < 10: # loop while count is less than 10
    print(count) #will print numbers 0 - 9
    count = count + 1 # must increase count

Lists

mylist = [2,3,4,5] # create a list

#select an item from a list
print (mylist[0]) #selects first item and displays 2

# len() determines the length of the list
print (len(mylist)) # displays 4

mylist.append(5) # adds an item to the end of the list
 

Multip­lic­ation and Exponents

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

Math

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

Addition

string + string
Combine together
string + number
CRASH!
number + number
Addition (Math)

Convert number to hexade­cimal

while True:
    

#get a number from the user
    user_number = input("Please enter a number: ")


    #convert to integer
    number = int(user_number)

    hex_string = ''
    while (number > 0):#the number is greater than 0)
        remainder = number % 16 #use Modulo %
        if remainder == 10:
            remainder = 'A'
        elif remainder == 11:
            remainder = 'B'
        elif remainder == 12:
            remainder = 'C'
        elif remainder == 13:
            remainder = 'D'
        elif remainder == 14:
            remainder = 'E'
        elif remainder == 15:
            remainder = 'F'


        hex_string = str(remainder) + hex_string #remainder + hex string
        number = number // 16#must use // when you divide

    #after the loop print the hex string
    print ("Hexadecimal string is 0x" + hex_string)

    #expected output - 5 = 101
    #excepted output - 3 = 11
    #excepted output - 2 = 10
 

Create function

# how to create a function

def nameOfFunction (myvar1, myvar2): # parameters or argu ments
    print ("hello") #must indent each line that is part of the function

    return myvar1 + myvar2

# function call

nameOfFunction ('hi', 'there') # a value for each argument


#write a function

# name : areaOfTriangle
# parameters : base height
# return : area

def areaOfTriangle (base, height):
     area = 0.5*base*height
     return area

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)

Decision Making­/Co­ndi­tional Statements

if 3 < 2: #if statement must compare two Booleans
    print ('3 is less than 2')
elif 4 < 2: #can have 0 or more elif statements
    print ('4 is less than 2')
elif 5 < 2:
    print ('5 is less than 2')
else: #can have 0 or 1 else statement at the end
    print ('none of the above are True')
 

Comments

No comments yet. Add yours below!

Add a Comment

Your Comment

Please enter your name.

    Please enter your email address

      Please enter your Comment.