The abstraction of Python's learning notes

First, create a function

>>> Import Math

>>> x=1

>>> y=math.sqrt

>>> callable (x) #显示False

>>> callable (y) #显示True

1, Def, used to create functions

>>> def hello (name)

>>> return ' Hello, ' +name+ '! '

>>> Print (Hello (' World '))

Show: Hello, World

2. Add description for function

>>> def Square (x):

>>> ' calculates the square of the number X. '

>>> return x *x

>>> square.__doc__

Display: ' Calculates the square of the number x. '

View functions via Help

>>> Help (Square)

Second, function parameters

1. Abstract function

>>> def init (data):

>>> data[' first ']={}

>>> data[' Middle ']={}

>>> data[' last ']={}

>>> storage={}

>>> Init (storage)

>>> Storage

Display: {' middle ': {}, ' last ': {}, ' first ': {}}

2. Collect parameters

>>> def print_params (X,y,z=3,*pospar,**keypar)

>>> print (x, y, z)

>>> Print (Pospar)

>>> Print (Keypar)

Display: 1 2 3 (5,6,7) {' foo ': 1, ' Bar ': 2}

Note: ' * ', a single asterisk is used to unite common parameters, ' * * ', two asterisks are used to handle keywords

3. Power Calculation Product

>>> Power (3,2)

Showing: 9

4, Interval, interval

>>> interval (10)

Display: [0,1,2,3,4,5,6,7,8,9]

>>> interval (1,5)

Display: [1,2,3,4]

5, when the parameter name and the global variable name, the global variable will be masked, not directly accessible, if you want to access, you need to use Globals

>>> def Combine (parameter):

>>> print (Parameter+globals () [' parameter '])

>>> parameter= ' Berry '

>>> combine (' shrub ')

Display: Shrubberry

The abstraction of Python's learning notes