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- Python: check if something is a member of a variable
- # built-in function - i n country='Deutschland' ' y ' in country False ' a ' in country True 'b' not in country True family= 'bro' in family False &# ...
- Python 2: index and change elements of variables
- family= # index from the very beginning, the sequence of each element is: 0 1 2 3 4 5 ... NOTE it starts from 0 ! family 'mom' family 'sis' family 'dog' list ( family ) # index from backwar ...
- Python 2: strings
- # double or single quotes 'hey yy' 'hey yy' hey yy 'hey yy' he's a handsome man he's a handsome man 'he ' s a handsome man' he's a handsome man 'he sai ...
- Python 3: Module math - mathematical functions
- import math # math.floor(x) returns the floor of x as a float, the largest integer value less than or equal to x. math.floor(9.2) 9.0 # math.sqrt(x) returns the square root of x. math.sqrt(81) 9.0 # math.pow(x,y) returns x raised to the power y ...
- Python: operators
- 1+2 3 9-2 7 3*5 15 -2 ** 4 # 乘方 -16 # 除法要注意啦 8/4 2 8/3 2 # python2 2.6666666666666665 # python3 8/3 . (or 8/3 .0 or 8 .0 /3) 2.6666666666666665 ...
- Python 2: open a webpage
- import urllib2 # the urllib2 module defines functions and classes which help in opening URLs (mostly HTTP) in a complex world - basic and digest authentication, redirections, cookies and more. url1 = 'http://www.oldbaileyonline.org/print.jsp?div=t17800628-33' response1 = ur ...
- Python 2: read and write from a file
- # send information to the Command Output print hello world # creat a new file and write it f = open('helloworld.txt','w') # creat a txt file in the working directory. w stands for write. when using w, the program will overwite whatever might ha ...
