On Wed, May 10, 2017 at 06:53:21PM -0700, Rafael Skovron wrote: > Sorry I left out the indents in my previous email. It seems like j is > always reset to zero. Why does j vary?
Because you run code that adds 1 to j. > Are there two different instances of j going on? No. Try to run the code in your head and see what happens. See below: > for i in range(1, 5): > j=0 > while j < i: > print(j, end = " ") > j += 1 We start by setting i = 1, then the body of the for-loop begins. That sets j = 0, and since 0 < 1, we enter the while-loop. Inside the while-loop, we print j (0), then add 1 to j which makes it 1. Then we return to the top of the while-loop. Since 1 is NOT less than 1, we exit the while-loop and return to the top of the for-loop. Now we set i = 2, and continue into the body of the for-loop. That sets j = 0 (again!) and since 0 < 2, we enter the while-loop. Inside the while-loop, we print j (0), then add 1 to j which makes it 1. Then we return to the top of the while-loop. Since 1 < 2, we continue inside the body, print j (1), then add 1 to j which makes it 2. Since 2 is not LESS than 2, we exit the while-loop and return to the top of the for-loop. Now we set i = 3, and continue into the body of the for-loop. That sets j = 0 (again!) and since 0 < 3, we enter the while-loop. Inside the while-loop, we follow the same steps and print 0, then 1, then 2, then exit the while-loop and return to the top of the for-loop. Now we set i = 4, and again continue into the while-loop to print 0, 1, 2 and finally 3, then exit the while-loop and return to the top of the for-loop, which is now complete. -- Steve _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
