转换为二进制并在Python中保持前导零

I'm trying to convert an integer to binary using the bin() function in Python. However, it always removes the leading zeros, which I actually need, such that the result is always 8-bit:

我正在尝试使用Python中的bin（）函数将整数转换为二进制。但是，它总是删除我实际需要的前导零，这样结果总是8位：

Example:

例：

bin(1) -> 0b1

# What I would like:
bin(1) -> 0b00000001

Is there a way of doing this?

有办法做到这一点吗？

8 个解决方案

#1

125

Use the format() function:

使用format（）函数：

>>> format(14, '#010b')
'0b00001110'

The format() function simply formats the input following the Format Specification mini language. The # makes the format include the 0b prefix, and the 010 size formats the output to fit in 10 characters width, with 0 padding; 2 characters for the 0b prefix, the other 8 for the binary digits.

format（）函数只是按照格式规范迷你语言格式化输入。＃使格式包含0b前缀，010大小格式化输出以适合10个字符宽度，0填充; 0b前缀为2个字符，二进制数字为8个字符。

This is the most compact and direct option.

这是最紧凑和直接的选择。

If you are putting the result in a larger string, use str.format() and put the second argument for the format() function after the colon of the placeholder {:..}:

如果要将结果放在一个更大的字符串中，请使用str.format（）并在占位符{：..}的冒号后面放置format（）函数的第二个参数：

>>> 'The produced output, in binary, is: {:#010b}'.format(14)
'The produced output, in binary, is: 0b00001110'

If you did not want the 0b prefix, simply drop the # and adjust the length of the field:

如果你不想要0b前缀，只需删除＃并调整字段的长度：

>>> format(14, '08b')
'00001110'

#2

>>> '{:08b}'.format(1)
'00000001'

See: Format Specification Mini-Language

请参阅：格式规范迷你语言

Note for Python 2.6 or older, you cannot omit the positional argument identifier before :, so use

对于Python 2.6或更早版本的注意事项，在以下情况之前不能省略位置参数标识符，因此请使用

>>> '{0:08b}'.format(1)
'00000001'

#3

I am using

我在用

bin(1)[2:].zfill(8)

will print

将打印

'00000001'

#4

You can use the string formatting mini language:

您可以使用字符串格式化迷你语言：

def binary(num, pre='0b', length=8, spacer=0):
    return '{0}{{:{1}>{2}}}'.format(pre, spacer, length).format(bin(num)[2:])

Demo:

演示：

print binary(1)

Output:

输出：

'0b00000001'

EDIT: based on @Martijn Pieters idea

编辑：基于@Martijn Pieters的想法

def binary(num, length=8):
    return format(num, '#0{}b'.format(length + 2))

#5

Sometimes you just want a simple one liner:

有时你只想要一个简单的衬垫：

binary = ''.join(['{0:08b}'.format(ord(x)) for x in input])

Python 3

#6

You can use something like this

你可以使用这样的东西

("{:0%db}"%length).format(num)

#7

module Adder(
    input upperBit, lowerBit, c_in,
    output s, c_out)

write gate1, gate2, gate3

xor (gate1, upperBit, lowerBit)
xor (s, gate1, c_in)
and (upperBit, lowerBit)
and (gate1, c_in)
or  (c_out, gate1, gate2)

endmodule

module ful_adder8(
    input [7:0) a, b
    input c_in
    output [7:0) s,
    output c_out)

write [7:0] carry

full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))
full_adder fa0(
    a(a[o])
    b(b[0])
    c_in(c_in)
    s(s[0])
    c_out(carry[0]))

endmodule
test
def split (n):
    return (n&0x1,n&0x2,n&0x4,n&0x8,n&0x10,n&0x20,n&0x40,n&0x80)
def glue (b0,b1,b2,b3,b4,b5,b6,b7,c):
    t = 0
    if b0:
        t += 1
    if b1:
        t += 2
    if b2:
        t += 4
    if b3:
        t += 8
    if b4:
        t += 16
    if b5:
        t += 32
    if b6:
        t += 64
    if b7:
        t += 128
    if c:
        t += 256
    return t


def myadd (a,b):
    (a0,a1,a2,a3,a4,a5,a6,a7) = split(a)
    (b0,b1,b2,b3,b4,b5,b6,b7) = split(b)
    (s0,s1,s2,s3,s4,s5,s6,s7,c) = addEightBits(a0,a1,a2,a3,a4,a5,a6,a7,b0,b1,b2,b3,b4,b5,b6,b7,false)
    return glue (s0,s1,s2,s3,s4,s5,s6,s7,c)

#8

-1

You can use zfill:

你可以使用zfill：

print str(1).zfill(2) 
print str(10).zfill(2) 
print str(100).zfill(2)

prints:

打印：

01
10
100

I like this solution, as it helps not only when outputting the number, but when you need to assign it to a variable... e.g. - x = str(datetime.date.today().month).zfill(2) will return x as '02' for the month of feb.

我喜欢这个解决方案，因为它不仅有助于输出数字，还有助于将其分配给变量......例如 - x = str（datetime.date.today（）。month）.zfill（2）将为feb月份返回x为'02'。

#1

125