I am trying to use list as an array and I want to enter integer values in the list so that I can perform some arithmetic on it.
m=int(input())
I always used this for getting some integer input from the user.
//creating an array
myArray=[]
inp=int(input("Please enter the length of array you wish to create"))
for m in range(inp):
myArray.append(int(input()))
print(myArray)
But this isn't working. Why?
Error :invalid literal for int() with base 10
Okay, since the input would be parsed as a string and int can only coerce strings that are just numbers into integers... you are in big trouble for a bad input as it would stop your program immediately.
I would suggest using a while loop and try-except exception statements for error handling.
NOTE for Python 2.x: Use raw_input since input would result in a NameError: name <input_string> is not defined if you pass characters without string quotations.
>>> my_array = [] # camelCase is not the convention in Python
>>>
>>> array_length = None
>>> while array_length is None:
... try:
... array_length = int(input("Please enter the length of array you wish to create: "))
... except ValueError:
... print("Invalid input - please enter a finite number for the array length.")
...
Please enter the length of array you wish to create: 4
>>>
>>> print(array_length)
4
>>> while len(my_array) < array_length:
... try:
... my_array.append(int(input()))
... except ValueError:
... print("Invalid input - please enter a number!")
...
1
abc
Invalid input - please enter a number!
2
3
4
>>>
>>> print(my_array)
[1, 2, 3, 4]
# -*- coding: utf-8 -*-
INVALID_NUMERIC_INPUT_MSG = "Invalid input - please enter a finite number with no spaces!"
KEYBOARD_INTERRUPTION_MSG = "Keyboard interruption: program exited."
def main():
my_array = []
print()
array_length = None
while array_length is None: # accept input until valid
try:
array_length = int(input("Please enter the length of array you wish to create: "))
except ValueError:
print(INVALID_NUMERIC_INPUT_MSG)
except KeyboardInterrupt:
print("\n" + KEYBOARD_INTERRUPTION_MSG)
quit()
print("Your array length is {}.".format(array_length))
print()
while len(my_array) < array_length:
try:
my_array.append(int(input()))
except ValueError:
print(INVALID_NUMERIC_INPUT_MSG)
except KeyboardInterrupt:
print("\n" + KEYBOARD_INTERRUPTION_MSG)
quit()
assert len(my_array) == array_length # check for program correctness
print()
print("Your array is: {}".format(my_array))
print()
if __name__ == '__main__':
main()
Running in my console:
$ python3 input-program.py
Please enter the length of array you wish to create: 4
Your array length is 4.
1
2
3
4
Your array is [1, 2, 3, 4]
print my_array print(my_array) is also giving me a syntax error? What is the actual syntax? I tried searching but didn't get it
raw_input in Python 3.x, but everything else still works. Does the SyntaxError point at the first parenthesis in print(my_array)? If so, it's most likely an indentation error in the console.The str to int coercion can be done by just trying it out, to see if it input was a number.
Here we make a zeroed array and a consecutively numbered array (a range)
In python you call an array a list
array = [0]
try:
array = array * int(raw_input('How long? ->'))
print array
except:
print "try using a number"
OR
try:
array = range(int(raw_input('How long? ->')))
print array
except:
print "try using a number"
PS this is Python v2 code not v3
ValueError: invalid literal for int() with base 10: ''Are you not seeing those final quotes with the literal it tried to parse?