Python – Loops and Iteration

1. Python – Loops and Iteration Lecture03

2. Sums What’s the sums of the numbers from 1 to 10? sum = 0 sum = sum + 1 sum = sum + 2 sum = sum + 3 sum = sum + 4 sum = sum + 5 sum = sum + 6 sum = sum + 7 sum = sum + 8 sum = sum + 9 sum = sum + 10 printsum

3. Sums What’s the sums of the numbers from 1 to 1000? sum = 0 for i inrange(1001): sum += i printsum

4. range() The range function generates an array up to its argument. range(start) range(start, stop) range(start, stop, increment)

5. Operator - in array = range(6) if5inarray: print"YEP!" for item inarray: print"YUP!"

6. For Loops When you know how many times you want to loop for x inrange(1,10): pass

7. While Loops For when you’re not sure how many times you want to iterate. while (condition): pass

8. Keywords for Iteration break continue pass

9. Break sum = 0 foriinrange(11): sum += 1 ifi == 5: break printsum

10. Continue sum = 0 foriinrange(11): sum += 1 ifi == 5: continue printsum

11. Pass sum = 0 foriinrange(11): sum += 1 ifi == 5: pass printsum

12. Nesting Loops Loops can contain loops: sum = 0 foriinrange(10): for j inrange(10): sum += 1 printsum

13. Printing a Square It can be accomplished the long way… print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *" print"* * * * * * * * * *"

14. Square – Deluxe Edition for row inrange(10): for column inrange(10): print"*", print""