python中number

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发布时间：2019-05-25

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To delete the reference to a number object using del. The syntax of the del statement is: del var1[,var2[,var3[....,varN]]]]

Python中不同数据类型之间的转换规则（限number）

1 复数 2 浮点数 3 长整形 4 整形

绝对值函数abs对复数的作用则是 x+yi abs=xX+ yy开平方

Number Type Conversion:

Type int(x) to convert x to a plain integer.

Type long(x) to convert x to a long integer.

Type float(x) to convert x to a floating-point number.

Type complex(x) to convert x to a complex number with real part x and imaginary part zero.

Type complex(x, y) to convert x and y to a complex number with real part x and imaginary part y. x and y are numeric expressions

Built-in Number Functions:

Mathematical Functions:

Python includes following functions that perform mathematical calculations.

Function	Returns ( description )
	The absolute value of x: the (positive) distance between x and zero.
	The ceiling of x: the smallest integer not less than x
	-1 if x < y, 0 if x == y, or 1 if x > y
	The exponential of x: e^x
	The absolute value of x.
	The floor of x: the largest integer not greater than x
	The natural logarithm of x, for x> 0
	The base-10 logarithm of x for x> 0 .
	The largest of its arguments: the value closest to positive infinity
	The smallest of its arguments: the value closest to negative infinity
	The fractional and integer parts of x in a two-item tuple. Both parts have the same sign as x. The integer part is returned as a float.
	The value of x**y.
	x rounded to n digits from the decimal point. Python rounds away from zero as a tie-breaker: round(0.5) is 1.0 and round(-0.5) is -1.0.
	The square root of x for x > 0

Random Number Functions:

Random numbers are used for games, simulations, testing, security, and privacy applications. Python includes following functions that are commonly used.

Function	Returns ( description )
	A random item from a list, tuple, or string.
	A randomly selected element from range(start, stop, step)
	A random float r, such that 0 is less than or equal to r and r is less than 1
	Sets the integer starting value used in generating random numbers. Call this function before calling any other random module function. Returns None.
	Randomizes the items of a list in place. Returns None.
	A random float r, such that x is less than or equal to r and r is less than y

Trigonometric Functions:

Python includes following functions that perform trigonometric calculations.

Function	Description
	Return the arc cosine of x, in radians.
	Return the arc sine of x, in radians.
	Return the arc tangent of x, in radians.
	Return atan(y / x), in radians.
	Return the cosine of x radians.
	Return the Euclidean norm, sqrt(xx + yy).
	Return the sine of x radians.
	Return the tangent of x radians.
	Converts angle x from radians to degrees.
	Converts angle x from degrees to radians.转化为弧度