Python Learning Note 1

According to a high-ticket answer to the Thu of the Great God Study
http://nbviewer.jupyter.org/github/lijin-THU/notes-python/tree/master/
Just sort of something I don't think I'm familiar with.
For Acmer or some familiar with C + + children's shoes should have some reference, I think
I think Python is a future language that will someday replace C++,java
To be more simplified
Just like the relationship between the Assembly and C.

CHAT1 Tools

Although I have learned a bit of python before, I hope this time we can learn the language more systematically and lay a good foundation for the future.

dict.get(key, default=None)# dict是字典类型，返回查找key的值# 如果不存在，返回default

%whos#查看当前变量空间%-f#清空变量空间

%%writefile hello_world.pyprint"hello world"# 将这行字写到hello_world.py当中去

%rmdir demo_test# 删除文件集%hist# 查看历史命令

sum?#使用??查看函数帮助和函数源代码

=12+13#_使用上一个cell的输出结果

After installing Anaconda for the first time, you can enter the following command at the command line to keep Anaconda up to date:

conda update condaconda update anaconda

Conda is a powerful tool that can be used to refer to its documentation.

You can also refer to its cheat sheet for a quick look at its usage.

You can use it to install, update, and uninstall third-party python toolkits:

conda<some package>conda<some package>conda<some package>

CHAT2 Part 1 A-TOUR-OF-PYTHON.IPYNB

import numpydel numpy# 撤销引入

="""helloworld"""print s# “”“来表示换行

Use of List

= [12.0‘hello‘5+1.0]a.append("world")

Use of Set

= {1234= {2345&|^ b#对称差，也就是两个集合所独有的元素

Use of Dictionary

= {‘dogs‘:5‘cats‘:4}d["pigs"]d.keys()d.values()

Numpy.array

= array([1234+2# python自带也是有array数组的，这里使用

Use of the list deduction formula

42964299

File operations

=open(‘data.txt‘‘w‘)f.write(‘1 2 3 4\n‘)f.write(‘2 3 4 5\n‘

function definition

def poly(x, a, b, c):    =***2+*+ c    return=1poly(array([123123)# 这里注意必须使用numpy的转化

The creation of class classes

class  person (): def  __init__  (self , First, last, age): self . First =  first self . Last = last self . Age =  age def  full_name (
    
     self ): 
     return  
     self . First 
     +  " +  self . Last person =  person ( ' Mertle ' ,  ' Sedgewick ' , 52 ) person.firstperson.full_name () Person.basasuya =  Dperson.basasuya # here you can find that the element of person is a  
     
 that can be added randomly.

=‘http://ichart.finance.yahoo.com/table.csv?s=GE&d=10&e=5&f=2013&g=d&a=0&b=2&c=1962&ignore=.csv‘import= urllib2.urlopen(url)# web使用

Python Learning Note 1