CODEWITHSUNDEEP
pythonpython-2.7raw-input
DanielTheRocketMan
DanielTheRocketMan

Reputation: 3249

Python: Strange behaviour of raw_input

The code below provides an unexpected answer when I use raw_input. Can anyone explain me what is happening and how to solve it?

import numpy as np
response = raw_input("What is your move? ")
response=np.array(response)
changingPositions=np.flatnonzero(response)
print changingPositions

response=np.array([0,1,0])
changingPositions=np.flatnonzero(response)
print changingPositions

The execution is:

What is your move? [0,1,0]
[0]
[1]

The expected answer is

[1]

Upvotes: 0

Views: 66

Answers (2)

Vincent
Vincent

Reputation: 1044

response is a string element. But you want an list.

so you need to parse the user input to a list. You should use input() instead of raw_input(), which parses the user input, or use eval(raw_input()) (eval() parses a string to an element...

But I suggest to surround this function with try..except, to check if the user input is valid, and also loop if input is still invalid:

import numpy as np

isValid = False

while !isValid:
    try:
        response = input("What is your move? ")
        isValid = True
    except:
        print("Input is not valid!!")

response=np.array(response)
changingPositions=np.flatnonzero(response)
print changingPositions

response=np.array([0,1,0])
changingPositions=np.flatnonzero(response)
print changingPositions

Upvotes: 1

BlackBear
BlackBear

Reputation: 22989

raw_input returns a string, in fact np.flatnonzero(np.array('adfsgh')) produces array([0]) too. So just make a list of ints:

In [1]: import numpy as np

In [2]: response = raw_input("What is your move? ")
What is your move? 0,1,0

In [3]: positions = np.array(map(int, response.split(',')))

In [4]: changing_positions = np.flatnonzero(positions)

In [5]: changing_positions
Out[5]: array([1])

Upvotes: 2

Related Questions