Python 內置函數進制轉換的用法（十進制轉二進制、八進制、十六進制）

使用Python內置函數：bin()、oct()、int()、hex()可實現進制轉換。

先看Python官方文檔中對這幾個內置函數的描述：

bin(x)
Convert an integer number to a binary string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.

oct(x)
Convert an integer number to an octal string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.

int([number | string[, base]])
Convert a number or string to an integer. If no arguments are given, return 0. If a number is given, return number.__int__(). Conversion of floating point numbers to integers truncates towards zero. A string must be a base-radix integer literal optionally preceded by ‘+’ or ‘-‘ (with no space in between) and optionally surrounded by whitespace. A base-n literal consists of the digits 0 to n-1, with ‘a’ to ‘z’ (or ‘A’ to ‘Z’) having values 10 to 35. The default base is 10. The allowed values are 0 and 2-36. Base-2, -8, and -16 literals can be optionally prefixed with 0b/0B, 0o/0O, or 0x/0X, as with integer literals in code. Base 0 means to interpret exactly as a code literal, so that the actual base is 2, 8, 10, or 16, and so that int('010', 0) is not legal, while int('010') is, as well as int('010', 8).

hex(x)
Convert an integer number to a hexadecimal string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.

	2進制	8進制	10進制	16進制
2進制	-	bin(int(x, 8))	bin(int(x, 10))	bin(int(x, 16))
8進制	oct(int(x, 2))	-	oct(int(x, 10))	oct(int(x, 16))
10進制	int(x, 2)	int(x, 8)	-	int(x, 16)
16進制	hex(int(x, 2))	hex(int(x, 8))	hex(int(x, 10))	-

bin()、oct()、hex()的返回值均爲字符串，且分別帶有0b、0o、0x前綴。