Use value of a variable as counter in python 3

Question

I want to take an input from the user and and store it in a variable, lets say k. Then use this k as a counter for a for loop.

while i<k: doesn't work! code:

k= input('number of points:')
p=[]
i=0
while i<k:
x=float(input('Enter value='))
p.append(x)
i=i+1

Output:

number of points:3
Traceback (most recent call last):
File "/home/ramupradip/tes.py", line 4, in <module>
while i<k:
TypeError: unorderable types: int() < str()

I also tried using range

for i in range(1,k)

which gave me an error: Traceback (most recent call last): File "/home/ramupradip/reflect.py", line 6, in for i in range(1,k): TypeError: 'str' object cannot be interpreted as an integer

what is k.....? is it int?Plz post errors that you getting — Deepak Ingole
– Deepak Ingole, Commented Sep 4, 2013 at 14:27

Óscar López · Accepted Answer · 2013-09-04 14:47:09Z

1

Read the input like this:

k = int(input('enter counter: '))

... I guess you forgot to convert the number to int, but it's impossible to tell if you don't show the relevant code. Other than that, the looping constructs shown in the question should work fine, but the first one is preferred in Python, just be careful with the indexes:

for i in range(1, k+1):
    # do something

Equivalently:

i = 1
while i <= k:
    # do something
    i += 1

edited Sep 4, 2013 at 14:47

answered Sep 4, 2013 at 14:41

Óscar López

237k38 gold badges321 silver badges391 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Superam Over a year ago

Thank you :) . It was the missing 'int' which was the problem.

OdraEncoded · Accepted Answer · 2013-09-04 14:51:51Z

0

That does not make any sense. You could want this:

for i in range(k):
     ...

Where k is the total number of iterations set by the user and i is a value that changes from 0 to k - 1. Or you could want this:

for k in range(x):
     ...

Where k is a value from 0 to x - 1 and the user input doesn't mean anything. Or you could want this:

for i in range(k, x):
    ...

Where k is the start value set by the user, x is a value set by the program and i is a value that starts from k and ends in x - 1

See the documentation for more info http://docs.python.org/3/library/functions.html#func-range

answered Sep 4, 2013 at 14:51

OdraEncoded

3,1853 gold badges26 silver badges36 bronze badges

1 Comment

Óscar López Over a year ago

You're changing the starting value of i, this is not equivalent to the code in the question. It might be possible that OP is only interested in looping k times (we can't tell by just looking at the current question), but if he is going to use i, the expected starting value is 1, according to the question

Collectives™ on Stack Overflow

Use value of a variable as counter in python 3

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related