• Three main types of Control Flow:
  • If / Else Statements 
    a = False
if a:
   print('It is true!')
     print('Also print this')
  • The above is an if block.
  • Can out-dent as well, for example: 
    a = False
if a:
   print('It is true!')
     print('Also print this')
print('Always print this')

    Will then print print('Always print this')

  • If a is true, it will print all of the below 3 lines: 
    a = True
if a:
   print('It is true!')
     print('Also print this')
print('Always print this')

    It is true! Also print this Always print this

  • To add an else statement, you can do: 
    a = True
if a:
   print('It is true!')
     print('Also print this')
else:
   print('It is false!')
print('Always print this')
  • Can add a lot of indents, for example: 
    a = True
b = True
if a:
   print('It is true!')
     print('Also print this')
     if b:
          print('Both are true')
else:
   print('It is false!')
print('Always print this')

    It is true! Also print this Both are true Always print this

  • Another example: 
    a = True
b = True
c = True
if a:
   print('It is true!')
     print('Also print this')
     if b:
          print('Both are true')
               if c:
                      print('All three are true')
else:
   print('It is false!')
print('Always print this')

    It is true! Also print this Both are true All three are true Always print this

  • If any of the above are set to False, you never reach line: print('All three are true')
  • In order to avoid excessive indenting, Python has another tool call the Loop
  • Loops
    • For Loops iterate over what Python calls iterables.
    • A list is a type of iterable: 
      a = [1,2,3,4,5]
for item in a:
  print(item)

      Outputs: 1 2 3 4 5

  • The item is just a variable being declared in the line.
  • While Loops
    • These keep looping until the boolean that is passed becomes false. 
      a = 0
while a < 5:
  print(a)
 a = a + 1
  • Without the following line, the above loop would not end: a = a + 1
    • Good to implement a while loop if conditions are changing.

Updated: