Python编程技巧

1. Python：基础编译器
2. NumPy：支持数组和矩阵
3. ipython：一个净强化的交互Python Shell，对探索NumPy的特性非常方便。
4. matplotlib：将允许你绘图
5. Scipy：在NumPy的基础上提供了很多科学模块

1. Python 索引从0开始，#作为注释符，未结束的条件行以：结尾，
numpy.zeros((m, n)) 和 numpy.ones((m, n))，a**b代表乘方，.transpose或.T代表转置，
a*b代表elementwise相乘，dot(a,b)代表矩阵乘，concatenate(a,b)矩阵的列链接

2. 创建一个数组
from numpy import *
import numpy as np
a=array([[1,2,3],[4,5,6]]);a.shape
b=arange(15);print b
b.reshape(3,5)
c=zeros((4,5));print c
d=ones((4,5));print d
e=add(c,arange(20).reshape(4,5))
f=dot(e,d);print f
np.array([[1, 2, 3, 4],[4, 5, 6, 7], [7, 8, 9, 10]], dtype=np.float)
np.arange(0,1,0.1)
np.linspace(0, 1, 12)
np.logspace(0, 2, 20)

3. ndarray的几个常用属性：shape,ndim,size,T,dtype
ndarray的比较有用的方法：tolist(),item(*args),dump(file),dumps(),reshape(),resize(),swapaxes(),flatten()
max,min,sum,cumsum,prod,cumprod,all,any,mean

4. 创建一个矩阵
a = np.matrix([[1,2,3],[5,5,6],[7,9,9]])

 

 

 

 

demo

import numpy as np

def main():
 print "hello world"
 a,b,c = 1,2,3
 print a
 print b
 print c
 helptext=""" 1
 2
 3"""
 print helptext
 string="hello world"
 print string[1]
 
 #mytest = raw_input("please input a number:")
 mytest = 10
 mytest = int(mytest)
 if mytest == 10:
  print "you input number is ten."
 elif mytest == 20:
  print "you input number is twenty."
 else:
  print "another number."

 a = 0
 while a < 5:
  a = a + 1
  print a
 else:
  print "a's value is five"

 mylist = "for statement"
 for word in mylist:
  print word
 else:
  print "End list"
 
 a = np.array((6,6));

 

# compile: python demo1.py
if __name__ == "__main__":
    main()  

 

参考：http://marinzou.blogbus.com/logs/65390334.html