python-2 function

Http://docs.python.org/3/library/functions.html or rookie Chinese information

1-Using functions

ABS ( -20)# Find the absolute # to find the maximum value # turn to intfloat ("12.34 " # turn into float # turn into a string # turn into BOOL type bool (' '

2-Custom functions

def my_abs (x):     if  not isinstance (x, (int, float)):         return 222    if x >= 0:        return  x    Else :         return -X

X,y= (111,222); The x value is the 111,y value is 222. function can return a tuple function directly

3-Parameters of the function

3.1 Default parameters, define default parameters Remember one thing: the default parameter must point to the immutable object!

defSUM (x, n=2):     returnx+Nsum (5)#equivalent to calling Power (5, 2):defEnroll (name, Gender, age=6, city='Beijing'):    Print('City :', City) Enroll ('Adam','M', city='Tianjin')#you can pass only the specified parameters

3.2 Variable Parameters

def # * indicates variable    sum = 0    for in  numbers:        = sum + N * n    return Sumcalc (# parameter called nums=[1,2,3]calc (# the second way 

3.3 Keyword Parameters

defPerson (name, age, * *kw):Print('Name:', Name,'Age :', Age,'Other :', kw) extra= {' City':'Beijing','Job':'Engineer'}person ('Jack', **extra)

3.4 Named keyword Parameters

defPerson (name, age, *args, city='Beijing', Job):Print(name, age, args, city, job) person ('Xiaofeng', 12,city='Shenzhin', job='Myjob') Extra= {' City':'Beijing','Job':'Engineer'}person ('Xiaofeng', 12,**extra)

3.5 parameter Combinations

defF1 (A, B, c=0, *args, * *kw):Print('A ='A'B ='B'C ='C'args =', args,'kw =', kw) args= (1, 2, 3, 4) kw= {'D': 99,'x':'#'}f1 (*args, **kw)#A = 1 b = 2 c = 3 args = (4,) kw = {' d ': ' X ': ' # '}

python-2 function