Page 1 - Lesson Note - Iterative Statement

Lesson Note
Iterative Statement

Iterative statement to use when a task has to be repeated.

Two types of loop statements in Python:
i) for loop – counting loops, the loops that repeat a certain number of times
ii) while loop - conditional loops that repeat until a certain condition is true

for loop
Syntax:
for <variable> in <sequence>:
statements_to_repeat

for x in [4, 5, 6, 7]: for x in range(4, 8): for x in range(10, 0, -2)
print (x) print (x*x) print (x*x)
Output Output Output
4 16 100
5 25 64
6 36 36
7 49 16
4
for ch in 'CALM' sum = 0
print(ch) for n in range (1, 11)
sum = sum + n
Output print (sum)
C
A OUTPUT
L 55
M

while loop

Syntax:
Evaluates the logical test condition, if true executes the while block, continues execution till
the test condition evaluates to TRUE.

while <logical expression>:
loop-body

x=4 a=5
while x>0: while a<=30:
print (x, "in loop") print (a)
x = x-1 a = a+5

Output Output
4 in loop 5
3 in loop 10
2 in loop 15
1 in loop 20

25