Lesson 9 Notes: Iteration (loop-de-loops)

• Print on Same Line
  • Adding a comma at the end of a print statement line will make the next print command appear on same line
  • Example:
    print num1, "+", num2, "=",
answer = input("")
• While …
  • The keyword while can be used to create a command loop.
  • while statements need an "incremented counter"
  • Example:
    while x<10:
    print x
    x = x+1
• Generalizing
  • To make sections of code reusable, instead of using constant values, use variables.
  • Example (not generalized):
    while x<12:
    print 2 *x
    x=x+1
  • Example (generalized):
    while x< max_num:
    print num*x
    x = x+1
• Making Tables
  • Tables can be created using the tab \t escape code in a string.
  • The "tab" keeps items lined up real pretty
  • Example:
    while x < 10:
    print item1, "\t", item2
    x = x+1
• Review
  • How can you make two lines of code print on same line?
  • What code can be used to create a well-aligned table?
  • How do you make a section of code repeat itself?
  • Give an example of how the principle of generalization can be applied.