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python help(int)

2018-06-18 00:07:00来源：未知阅读 ()

class int(object)

| int(x=0) -> integer
| int(x, base=10) -> integer
|

| Convert a number or string to an integer, or return 0 if no arguments
| are given. If x is a number, return x.__int__(). For floating point
| numbers, this truncates towards zero.

| If x is not a number or if base is given, then x must be a string,
| bytes, or bytearray instance representing an integer literal in the
| given base. The literal can be preceded by '+' or '-' and be surrounded
| by whitespace. The base defaults to 10. Valid bases are 0 and 2-36.
| Base 0 means to interpret the base from the string as an integer literal.

| 将一个数字或字符串转换成整数，没有参数的时候为默认值0。如果参数时数字，调用__init__()，参数为浮点数，会发生截取。

|当x参数时不是数字时，或者有参数base，那么x参数一定是字面值是整数的字符串，字节流，或者是字节数组。这个字面值可以有正负号，前后可以有空格。

|base参数默认是10，base允许是0,2到36。如果base是0的时候，会根据字符串的字面值判断base的值。

1 a = int('100', 2)
2 print(a)
3 a = int('0b100', 0)
4 print(a)

1 4
2 4

1 print(abs(-10))
2 print(abs(10))

1 10
2 10

|
| __add__(self, value, /)
| Return self+value.

1 print(10 + 10 + 10)

1 30

|
| __and__(self, value, /)
| Return self&value.

1 print(1 & 3)

1 1

|
| __bool__(self, /)
| self != 0

1 if 1:
2     print("True")
3 if 0:
4     pass
5 else:
6     print("False")

1 True
2 False

|
| __ceil__(...)
| Ceiling of an Integral returns itself.

返回一个大于或者等于x的最小整数。

1 import math
2 print(math.ceil(10))
3 print(math.ceil(9.2))
4 print(math.ceil(-8.2))

1 10
2 10
3 -8

|
| __divmod__(self, value, /)
| Return divmod(self, value).

返回一个元组，一个值是x//y，第二个值是x%y。

1 print(divmod(10, 3))

1 (3, 1)

|
| __eq__(self, value, /)
| Return self==value.

1 print(5 == 5)

1 True

|
| __float__(self, /)
| float(self)

1 print(float(5))

1 5.0

|
| __floor__(...)
| Flooring an Integral returns itself.

返回数字的下舍整数。

1 >>> import math
2 >>> math.floor(5)
3 5
4 >>> math.floor(5.1)
5 5
6 >>> math.floor(-5.1)
7 -6

|
| __floordiv__(self, value, /)
| Return self//value.

地板除。

1 >>> 5//2
2 2

|
| __format__(...)
| default object formatter

|
| __ge__(self, value, /)
| Return self>=value.

1 >>> 10 >= 5
2 True

|
| __getattribute__(self, name, /)
| Return getattr(self, name).

|
| __getnewargs__(...)

|
| __gt__(self, value, /)
| Return self>value.

1 >>> 10 > 5
2 True

|
| __hash__(self, /)
| Return hash(self).

获取一个对象（字符串或者数值等）的哈希值。

1 >>> hash(15)
2 15
3 >>> hash(15.5)
4 1152921504606846991
5 >>> hash('wang')
6 -1275867606344747311

|
| __index__(self, /)
| Return self converted to an integer, if self is suitable for use as an index into a list.

|
| __int__(self, /)
| int(self)

1 >>> int(10)
2 10
3 >>> int(10.10)
4 10

|
| __invert__(self, /)
| ~self

1 >>> ~0
2 -1
3 >>> ~1
4 -2
5 >>> ~-1
6 0
7 >>> ~-2
8 1

|
| __le__(self, value, /)
| Return self<=value.

1 >>> 10 <= 5
2 False

|
| __lshift__(self, value, /)
| Return self<<value.

1 >>> 1 << 1
2 2

|
| __lt__(self, value, /)
| Return self<value.

1 >>> 1 < 1
2 False

|
| __mod__(self, value, /)
| Return self%value.

1 >>> 5 % 2
2 1

|
| __mul__(self, value, /)
| Return self*value.

1 >>> 5 * 2
2 10

|
| __ne__(self, value, /)
| Return self!=value.

1 >>> 5 != 2
2 True

|
| __neg__(self, /)
| -self

1 >>> -10
2 -10
3 >>> --10
4 10

|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.

|
| __or__(self, value, /)
| Return self|value.

1 >>> 1 | 0
2 1

|
| __pos__(self, /)
| +self

1 >>> +5
2 5
3 >>> +-5
4 -5

|
| __pow__(self, value, mod=None, /)
| Return pow(self, value, mod).

1 >>> pow(2, 2)
2 4
3 >>> pow(3, 3)
4 27

|
| __radd__(self, value, /)
| Return value+self.

|
| __repr__(self, /)
| Return repr(self).

1 >>> repr(10)
2 '10'

|
| __str__(self, /)
| Return str(self).
|
| __sub__(self, value, /)
| Return self-value.
|
| __truediv__(self, value, /)
| Return self/value.
|
| __trunc__(...)
| Truncating an Integral returns itself.
|
| __xor__(self, value, /)
| Return self^value.
|
| bit_length(...)
| int.bit_length() -> int
|
| Number of bits necessary to represent self in binary.
| >>> bin(37)
| '0b100101'
| >>> (37).bit_length()
| 6
|
| conjugate(...)
| Returns self, the complex conjugate of any int.
|
| from_bytes(...) from builtins.type
| int.from_bytes(bytes, byteorder, *, signed=False) -> int
|
| Return the integer represented by the given array of bytes.
|
| The bytes argument must be a bytes-like object (e.g. bytes or bytearray).
|
| The byteorder argument determines the byte order used to represent the
| integer. If byteorder is 'big', the most significant byte is at the
| beginning of the byte array. If byteorder is 'little', the most
| significant byte is at the end of the byte array. To request the native
| byte order of the host system, use `sys.byteorder' as the byte order value.
|
| The signed keyword-only argument indicates whether two's complement is
| used to represent the integer.
|
| to_bytes(...)
| int.to_bytes(length, byteorder, *, signed=False) -> bytes
|
| Return an array of bytes representing an integer.
|
| The integer is represented using length bytes. An OverflowError is
| raised if the integer is not representable with the given number of
| bytes.
|
| The byteorder argument determines the byte order used to represent the
| integer. If byteorder is 'big', the most significant byte is at the
| beginning of the byte array. If byteorder is 'little', the most
| significant byte is at the end of the byte array. To request the native
| byte order of the host system, use `sys.byteorder' as the byte order value.
|
| The signed keyword-only argument determines whether two's complement is
| used to represent the integer. If signed is False and a negative integer
| is given, an OverflowError is raised.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| denominator
| the denominator of a rational number in lowest terms
|
| imag
| the imaginary part of a complex number
|
| numerator
| the numerator of a rational number in lowest terms
|
| real
| the real part of a complex number