CS 111 w20 lecture 11 outline

1 Poll

s = "that's good soup!"
acc = "mmm"
for i in range(1, len(s), 2):
    acc = acc + s[i]
print(acc)

def zero(vec):
    for i in range(len(vec)):
        vec[i] = 0
vec = [1,2,3]
print(zero(vec))

def swap_first(xs, ys):
    t = xs[0]
    xs[0] = ys[0]
    ys[0] = t
v1 = [1, 2, 3]
v2 = ("a", "b", "c")
swap_first(v1, v2)
print(v1)

2 `while` loop

while CONDITION:
    BODY

Each time through the loop (including the first time), CONDITION is evaluated
if CONDITION is True, the loop goes through BODY again
if CONDITION is False, the program skips to the first unindented line after the loop
while True: — infinite loop???