python tutorial 1

环境变量
系统shell查找路径（用于发现“python"）： PATH
python模块查找路径（用于导入）：PYTHONPATH
python交互启动文件路径：PYTHONSTARTUP
GUI扩展变量（Tkinter）： TCL_LIBARAY, TK_LIBRARY


内置类型对象
number : 123, 3.12, 99L, 0x9ff, 0177, 4+3j, 4.0e+10
string: 'spam', "don't"
list: [1, [2, 'three'], 4]
dictionary: {'food':'spam', 'taste': 'yum'}
tuple: (1, 'spam', 4, 'U')
file: text = open('egg', 'r').read()

Python : Modules

* create a file called fibo.py
# Fibonacci numbers module

def fib(n): # write Fibonacci series up to n
a, b = 0, 1
while b < b =" b," result =" []" b =" 0," b =" b,">>> import fibo
>>> fibo.fib(1000)
1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
>>> fibo.fib2(100)
[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
>>> fibo.__name__
'fibo'

>>> from fibo import fib, fib2
>>> fib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377

* Modules search path
PYTHONPATH

* Standard modules
** sys
** dir
>>> import fibo, sys
>>> dir(fibo)

* Packages
Sound/ Top-level package
__init__.py Initialize the sound package
Formats/ Subpackage for file format conversions
__init__.py
wavread.py
wavwrite.py
aiffread.py
aiffwrite.py
auread.py
auwrite.py
...
Effects/ Subpackage for sound effects
__init__.py
echo.py
surround.py
reverse.py
...
Filters/ Subpackage for filters
__init__.py
equalizer.py
vocoder.py
karaoke.py
...

The __init__.py files are required to make Python treat the directories as containing packages;