我需要编写一个python代码来接受用户的数字并将其转换为二进制而不使用函数或bin吗？

Question

Decimal to binary in Python

I did this code and I am getting a zero(0) at the end of the answer I don't want that zero

num=int(input("Enter a number:"))
a=0
a=str(a)
while num>0:
    a=a+str(num%2)
    num=int(num/2)
print(a[::-1],end='')

My Output : Enter a number:42 1010100

I don't need the final zero I need

Enter a number:42 101010

Answer 1

A better formation:

num = int(input("Enter a number: "))
a = ''
while num > 0:
    a += str(num % 2)
    num //= 2
print(a[::-1])

Enter a number: 42
101010

As a beginner, you should pay attention to your programming habits to make your code more concise and readable.

Answer 2

设置a=""并删除a = str（a）应该可以解决您的问题

Answer 3

Rather than initialize a to "0" , just initialize it to the empty string:

num=int(input("Enter a number:"))
a=""
while num>0:
    a=a+str(num%2)
    num=int(num/2)
print(a[::-1],end='')