while loop

while loop iterates when condition is True until condition is False or when immediate break statement inside the loop body is run.
a=0
while a<5:
print(a)
a+=1
or calculate Fibonacci series
a, b = 0, 1
fib=[]
while True:
# print(a)
if len(fib)>=10:
break
else:
fib.append(a)
a, b = b, a+b
print(fib[-1], end=" ")