Learn the python the hard way (Day 2)
Day 2, I'll introduce raw_input(), it will help us give user some information, and let them to decide what road to go.
>>> name = raw_input("what's your name:")
what's your name:terry
>>> print name
terry
raw_input()
raw_input(...)
raw_input([prompt]) -> string
Read a string from standard input. The trailing newline is stripped.
If the user hits EOF (Unix: Ctl-D, Windows: Ctl-Z+Return), raise EOFError.
On Unix, GNU readline is used if enabled. The prompt string, if given,
is printed without a trailing newline before reading.
give some parameter at the beginning, it is very interesting.
1 #parameter, package, variable 2 3 from sys import argv 4 5 script,first,second, third = argv 6 7 print "The script is called:", script 8 9 print "Your first viriable is :", first 10 11 print "Your sencond viriable is :", second 12 13 print "Your third viriable is :", third --------------------------------------------------------------- [root@huan python_zed]# python ex13.py a b c The script is called: ex13.py Your first viriable is : a Your sencond viriable is : b Your third viriable is : c
user have lots of chance to decide which they like, is it good?
now I'll introduce another useful tool -- file operation 1 # read file
2 from sys import argv # import argv module
3
4 script,filename = argv # unpack argv to script and filename varible
5
6 txt = open(filename) # open a filename and return the file address to txt
7
8 print "Here's your file %r:" % filename # print filename
9
10 print txt.read() # txt get the file and read content. than print them
11
12 txt.close() # close file
13
14 print "Type the filename again:" # print reminder
15
16 file_again = raw_input(">") # get file name again by manual
17
18 txt_again = open(file_again) # open filename by your input
19
20 print txt_again.readline() # print the content of your file_again
21
22 txt_again.close()
------------------------------------------
[root@alicia ex15]# python ex15.py ex15_sample.txt
Here's your file 'ex15_sample.txt':
This is stuff I typed into a file.
It is really cool stuff.
Lots and lots of un to have in here.
Type the filename again:
>ex15_sample.txt
This is stuff I typed into a file.
read and write file to complete copy file feature
[root@huan ex17]# vi ex17.py 1 # more of file operation 2 3 from sys import argv # import argv 4 5 from os.path import exists # import exists,if filename exist,return true 6 7 script, from_file, to_file = argv #unpack for argv 8 10 11 # we could do these two on one line too,how? 12 13 input = open(from_file) # open from_file 14 15 indata= input.read() # read content of from_file 16 17 print "The input file is %d bytes long" % len(indata) # length of from_file 18 19 print "Does the output file exist? %r " %exists(to_file) # to_file is exist? 20 21 print "Ready, hit RETURN to continue, CTRL-C to abort." 22 23 raw_input() #if CTRL-C everthing is over, the others will continue 24 25 output = open(to_file,'w') # open to_file 26 27 output.write(indata) # write from_file to to_file 28 29 print "Alright, all done." 30 31 output.close() 32 33 input.close() ---------------------------------------------------------- [root@huan ex17]# python ex17.py test.txt copied.txt Coping from test.txt to copied.txt The input file is 99 bytes long Does the output file exist? True Ready, hit RETURN to continue, CTRL-C to abort. s Alright, all done. [root@huan ex17]# cat copied.txt This is stuff I typed into a file. It is really cool stuff. Lots and lots of un to have in here.another easy way:
[root@huan ex17]# vi ex17_homework.py 1 # more of file operation 2 3 from sys import argv # import argv 4 5 from os.path import exists # import exists,if filename exist,return true 6 7 script, from_file, to_file = argv 8 9 open(to_file,'w').write(open(from_file).read())