[Learn] Python Core Programming Learning Notes (ii)

2. Python Start 2.1 Print

1 Print " Hello world! "

2.2

_: The value of the last expression

>>: Output redirection

%: Prints the formatted string and values for the style, and the value after% is a tuple object, with "()" containing the

Print "%s is a number%d."%  ("Python", 6)ImportSYSPrint>> Sys.stderr,"msg"file= Open ("filename","a")Print>> file,"File MSG."file.close () Hello= Raw_input ("Hello:")Print "Num:%d."% (int (hello))

2.3

#: Comment Symbol

2.4 operator

+-*///% * *

< <= > >= = = = = <>

And Or not

* *: exponentiation

2.5 Variables and Assignments

2.6 Numbers

int long bool Float complex

Decimal

Import Decimal

Decimal. Decimal ("1.1")

1.1-1.1000001 (usually counted as such)

2.7 string

Support for [],[:] Operations

2.8 Lists and tuples

Index starting from 0, support slicing operation ': '

List: [] can change values

Tuple: () cannot change value

2.9 Dictionaries

{' key ': ' Value '}

2.10 Code blocks aligned with indentation

　　

2.11 If

　　

if condition:    something

2.12 while

 while condition:    something

2.13 for

 for iteration:    something

Range (): extent

Enumerate (): Enumeration

2.14

　　

 for inch if  not x% 2]

2.15 Open () file ()

Fobj = open ("Filename""R") for in fobj:      print Eachline,      #  ', '  causes print to not print line breaks fobj.close ()

2.16 Exceptions

Try :    somethingexcept  IOError, E:    except

2.17 Functions

def function_name ():    something

Class 2.18

class ClassName (baseclassname):    something

2.19 Modules

Import Module_name

2.20 Utility Functions

Dir ([obj]) help ([obj]) int () Len () Open () range () raw_input () str () type ()

[Learn] Python Core Programming Learning Notes (ii)