"Turn" Python Learning (5)--Data type

Transfer from http://www.cnblogs.com/BeginMan/archive/2013/06/08/3125876.html

One, standard type function

CMP (): Compare size

STR (): Convert to String

Type (): Types

cmp (...)      cmp (x, y) - > integer      return negative (negative) if x<y, zero ( 0 if x = = y, positive (positive) if x>y.

As follows:

>>> cmp(5,3.2)1>>> cmp(3.5,8)-1

Ii. Conversion of factory functions

There is a loss of precision

>>> int(1.847)1>>> long(42)42L>>> float(42)42.0>>> complex(42)(42+0j)>>> complex(2.4,-8)(2.3999999999999999-8j)

Third, function function

For numeric operations: ASB (), coerce (), Divmod (), POW (), round ()

ASB (): Absolute: Absolute, complete, authoritarian, N: Absolute

>>> abs(-1)1

coerce ():Vt. Force, Force,
Type conversions, but provides a custom two numeric type conversion instead of relying on a Python interpreter. Returns a meta-ancestor that has a mandatory behavior.
Coerce (...)
Coerce (x, y) (x1, y1)

Return a tuple consisting of the numeric arguments converted to
A common type, using the same rules as used by arithmetic operations.
If coercion is not possible, raise TypeError.

>>> coerce(1,2)(1, 2)>>> coerce(1.2,2l)(1.2, 2.0)>>> coerce(1.2,2)(1.2, 2.0)>>> coerce(1,2.3)(1.0, 2.2999999999999998)>>> coerce(1j,123)(1j, (123+0j))

Divmod ():. Divmod divides the remainder, returns the Ganso of the containing quotient and the remainder

>>> divmod(10,3)(3, 1)>>> divmod(3,10)(0, 3)>>> divmod(10,2.5)(4.0, 0.0)

Pow ():power of a number: the meaning of the exponent

Both POW () and * * can achieve exponential operations, and POW () is born first.

>>> pow(2,5)32>>> 2**532

Round (): Rounding

Round (...)
Round (number[, ndigits]), floating point number

Round a number to a given precision in decimal digits (default 0 digits).
This is always returns a floating point number. Precision may negative.

>>> round(1.234,2)1.23>>> round(3.14)3.0>>> for each in range(10):         print round(math.pi,each)    3.03.13.143.1423.14163.141593.1415933.14159273.141592653.141592654

Iv. functions for integers only

Oct ():octonary number system octal string form

>>> oct(255)‘0377‘

Hex (): Hexadecimal number system hex string form

>>> hex(255)‘0xff‘

ASCII Code conversion function

Ord (): Ordinal: Ordinal, converting character to corresponding integer value

>>> ord(‘A‘)65

Chr (): Char: Single character, numeric pair should be an ASCII character

>>> chr(65)‘A‘

Five, operator

>>> x>=80 and x<=100True>>> 80<=x<=100True-----------------------------总是写错：>>> 80=

Vi. Pragmatism

1. Score Level

def result(x):     dic = { 9 : ‘A‘ , 8 : ‘B‘ , 7 : ‘C‘ , 6 : ‘D‘ }     myre = x / 10     for obj in sorted (dic.keys(),reverse = True ):         if myre> = obj:             out = dic[obj]             break         else :             out = ‘F‘     return out if __name__ = = "__main__" :      sorce = input ( ‘Enter your sorce:‘ )

    print‘level:%s‘%result(sorce) 


"Turn" Python Learning (5)--Data type