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一、The development of Python
1、Two types of program:
Type 1：Python,Java,PHP,C#,Go,ruby,C++…… >>>byte code
Type 2: C,assembler >>>machine code
2、Comparison between the frequencyly used language
PHP: suitable for website,have limitations
Python,Java: be suitable for website and background program
---Python :high execution,low development
---Java :high development,low execution
Cause Python is more easier to compile than Java
二、The type of Python
Jpython,Ironpython,CPython(commonly used),JavaScript Python,Rubypython
Pypy:developed by Cpython
三、The basic use of Python
1、the suffix：
The suffix is not limited but if without '.py' will lead some failure.
2、Two executive method:
(1)、.py route
（2)、In the explain device :insert real time and get the real implement results
3、explain the device route: #!/use/bin/env Python
4、Python 2 coding: # -*- coding:utf8 -*-
Eg:AscII 8bits(not enough) unicode 16bits(a waste of bits);
Utf-8 :Can distribute the bytes according to the situation
5、execute an operation
Print: wait until input value and then replace the values
1) Remind the user input username and password
2) Insert the username and password
3)Check
4)correct:log in;wrong:log failure
6、Variable :word+number+underline
1) number can't be the head and don't conclude key words such as:'as','and','from','except','for','exec','del'…
2) quotation marks:"";'':must be a pair
3) The algorithm of string: plus and multiple
Supplement : the algorithm of number:+、_、*、/、%、** 、//
7、if sentence
1) Compared with C :①the strict use of TAB key.②no use of() and {}in some cases
2) if elif else
3) the use of pass
8、while sentence
1) dead circulation :while 1==1
2) conditional while
Supplement:
1) while else
2) Continue: terminate the current circle and start the next round
Break:terminate the whole circle
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