After using 2 loops in a list, the first element is removed from it automatically in Python

I made a program in which the user enters some integers and python displays how many even and odd numbers you entered. The code is the following:

```ev_od_list = []
even = []
odd = []

number = int(input("Enter an integer(entering 0 would end the process): "))

while number != 0:
number = int(input("Enter an integer(entering 0 would end the process): "))
ev_od_list.append(number)

for i in ev_od_list:
if i % 2 == 0:
even.append(i)

even.remove(0)
print("The number of even numbers you entered is:", len(even))

for j in ev_od_list:
if j % 2 != 0:
odd.append(j)

print(ev_od_list)
print("The number of odd numbers you entered is:", len(odd))
```

And the output…

```Enter an integer(entering 0 would end the process): 1
Enter an integer(entering 0 would end the process): 2
Enter an integer(entering 0 would end the process): 3
Enter an integer(entering 0 would end the process): 4
Enter an integer(entering 0 would end the process): 5
Enter an integer(entering 0 would end the process): 6
Enter an integer(entering 0 would end the process): 7
Enter an integer(entering 0 would end the process): 8
Enter an integer(entering 0 would end the process): 9
Enter an integer(entering 0 would end the process): 10
Enter an integer(entering 0 would end the process): 0
The number of even numbers you entered is: 5
[2, 3, 4, 5, 6, 7, 8, 9, 10, 0]
The number of odd numbers you entered is: 4
```

In the second last line, you may notice that 1 has been removed from the list automatically. So, why is this happening?

The reason is you have a first call to `input()` which is overwritten by another call of `input()` and append the number after the second `input()` call. Here is the working code with much optimisations:

```even = []
odd = []

number = int(input("Enter an integer(entering 0 would end the process): "))

while number != 0:
if number != 0:
if number % 2 == 0:
even.append(number)
else:
odd.append(number)
number = int(input("Enter an integer(entering 0 would end the process): "))

print("The number of even numbers you entered is:", len(even))
print("The number of odd numbers you entered is:", len(odd))
```