Using Python to convert integer to binary

Are you aware of the builtin bin function?

>>> bin(100)
'0b1100100'
>>> bin(1)
'0b1'
>>> bin(0)
'0b0'

You are on the right track, you just need to save the digits in a variable somewhere instead of just printing them to the screen:

num_str = input("Please give me a integer: ")

num_int = int(num_str)

num_bin_reversed = ''

while num_int > 0:

    if num_int % 2 == 0:
        num_int = int(num_int / 2)
        num_remainder = 1
        print("The remainder is:", 0)
        num_bin_reversed += '0'

    elif num_int % 2 == 1:
        num_int = int(num_int / 2)
        num_remainder = 1
        print("The remainder is:", 1)
        num_bin_reversed += '1'

num_bin = num_bin_reversed[::-1]
if int(num_str) > 0:
  assert '0b' + num_bin == bin(int(num_str))

Now, try to fix it by making it work with negative numbers and 0 too!

#First off yes there is an easier way to convert i.e bin(int) but where is the fun in that


"""First we ask the user to input a number. In Python 3+ raw input is gone
so the variable integer_number will actually be a string"""

integer_number = input('Please input an integer') #get integer whole number off user

"""We could use int(input('Please input an integer')) but we don't want to overload
anyones brains so we show casting instead"""

'''Next we convert the string to an integer value (cast). Unless the user enters text
then the program will crash. You need to put your own error detection in'''

integer_number = int(integer_number)

"""initialise a variable name result and assign it nothing.
This so we can add to it later. You can't add things to a place that doesn't exist"""

result = ''  

'''since we are creating an 8bit binary maximum possible number of 255
we set the for loop to 8 (dont forget that x starts at 0'''
for x in range(8):
    #The variable in the for loop will increase by 1 each time
    #Next we get the modulos of the integer_number and assign it to the variable r
    r = integer_number % 2 

    #then we divide integer number by two and put the value back in integer_value
    #we use // instead of / for int division els it will be converted to a float point  variable
    integer_number = integer_number//2

    #Here we append the string value of r which is an integer to result
    result += str(r)


    #This then loops back to the for loop whilst x<8

#then we assign the reverse of result using [::-1] to result
result = result[::-1]

#print out the result
print(result)

#This is the same code as the one above it's just without comments
#This program takes a number from the user and turns it into an 8bit binary string

integer_number = int(input('Please input an integer'))

result = ''  

for x in range(8):

    r = integer_number % 2 
    integer_number = integer_number//2
    result += str(r)

result = result[::-1]

print(result)

here is a code that works in python 3.3.0 the converts binary to integer and integer to binary, JUST COPY AND PASTE!!!

def B2D():
    decnum = int(input("Please enter a binary number"), 2)
    print(decnum)
    welcome()
def D2B():
    integer_number = input('Please input an integer')
    integer_number = int(integer_number)
    result = ''  
    for x in range(8):
        r = integer_number % 2
        integer_number = integer_number//2
        result += str(r)
    result = result[::-1]
    print(result)
    welcome()
def welcome():
    print("*********************************************************")
    print ("Welcome to the binary converter program")
    print ("What would you like to do?")
    print ("Type 1 to convert from denary to binary")
    print ("Type 2 to convert from binary to denary")
    print ("Type 3 to exit out of this program")
    choice = input("")
    if choice == '1':
        D2B()
    elif choice == '2':
        B2D()
    elif choice == '3':
        print("Goodbye")
        exit
welcome()