For some reason this code doesn't print anything and doesn't stop running, can anybody tell me what is going wrong here?
l = [1,2]
i = 0
k = l[i]+l[i+1]
while k <= 10:
l.append(k)
i += 1
print l
5 Answers
The value of k (and therefore the loop condition) is set before the loop using the current value of i (0), and never changes during the loop execution. You would have to reassign k based on the new value for i inside the loop for it to change.
Comments
Python evaluates the value of k so that k isn't the expression, but the result of that expression:
k = l[i]+l[i+1] # In your case it's l[0] + l[1] = 3
You probably want to evaluate k every loop:
l = [1,2]
i = 0
for i in range(0, 10 + 1):
l.append(l[i] + l[i + 1])
print l
And just for fun, a more Pythonic Fibonacci sequence generator (literally):
def Fibonacci():
a, b = 0, 1
while True:
yield a
a += b
a, b = b, a
for n in Fibonacci():
raw_input(n)
Comments
Just move the line with k in it:
l = [1,2]
i = 0
k = l[i]+l[i+1]
while k <= 10:
l.append(k)
i += 1
k = l[i]+l[i+1]
print l
Comments
You're not doing any changes to the k variable. Once you calculate the value of K, the code gets stock in the while loop because the value of k never changes, you simply keep appending the value of k to the list.
Comments
not sure about python, but looks like you update the value of K ever also, not sure what is the scope of the while loop in python syntax.
kin the while loop.