Review Python BASICS (3)

1. Python input raw_input () function.

 
A = raw_input ()#The result is a string.A = int (raw_input ())#If you want to get an int, you can only do this.
 

If special characters such as \ t \ n are input, % R outputs \ t, \ n, and % s outputs \ t and \ n.

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 Print   "  How old are you?  "  Age = Raw_input ()  Print   "  How tall are you? "  Height = Raw_input ()  Print   "  How much do you weight?  "  Weight = Raw_input ()  Print   "  So, you are % R old, % R tall and % R heavy.  " % (Age, height, weight)  Print  "  So, you are % s old, % s tall and % s heavy.  " % (Age, height, weight)  Print   "  So, you are % d old, % d tall and % d heavy.  " % (INT (AGE), INT (height), INT (weight ))

Output

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How old are you? \ Thow tall are you? \ Nhow much do you weight?111So, you are'\ T'Old,'\ N'TallAnd '111'Heavy. So, you are \ t old, \ n tallAnd111 heavy.
 

This is usually the case.

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Age = raw_input ("How old are you?") Height= Raw_input ("How tall are you?") Weight= Raw_input ("How much are you weight?")Print "So, you're % R old, % R tall and % R heavy."% (Age, height, weight)
 

Differences between input and raw_input

When the input is a pure number

• Input returns numeric values, such as int and float.
• Raw_inpout returns the string type and the string type.

Input string as expression

Input calculates the number expression in the string, but raw_input does not.

For example, enter "57 + 3 ":

• • Input returns an integer of 60.
  • Raw_input will get the string "57 + 3"

Actually

 
DefInput (prompt ):Return(Eval (raw_input (prompt )))
 

2. Run the following command to view the doc in Windows:

 
Python-M pydoc raw_input
 

3. How to Write parameters when running a Python script.

ViewCode

 From Sys Import  Argvscript, First, Second, Third = Argv Print   "  The script is called:  "  , Script  Print   "  Your first variable is:  "  , First  Print   "  Your second variable is:  "  , Second  Print   " Your third variable is:  " , Third

Argv is similar to main (string [] ARGs) in Java ). But argv needs to specify the number of parameters, and the number of parameters must match when running the script. Otherwise, an error is returned. And the first parameter is ex13.py in Python ex13.py 1 1.

If the number of parameters is incorrect, the output is as follows:

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E: \ SkyDrive \ Python \ the hard way to learn Python> Python ex13.py 1 2 3 4Traceback (most recent call last): File"Ex13.py", Line 2,In<Module>Script, First, Second, Third=Argvvalueerror: too has values to unpack
 

4. Read and print the file

When reading a file from a script, it is best to use the file name as the script parameter. The following is the code

FromSysImportArgvscript, filename=Argvtxt=Open (filename)PrintTXT. Read ()
TXT. Close () file_name_again= Raw_input ("The filename you want to print \ n>")PrintOpen (file_name_again). Read ()
 

Output

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E: \ SkyDrive \ Python \ the hard way to learn Python>Python ex15.py ex15_sample.txtthisIsStuff I typed into a file. ItIsReally cool stuff. LotsAndLots of fun to haveInHere. The filename you wantPrint>Ex15_sample.txtthisIsStuff I typed into a file. ItIsReally cool stuff. LotsAndLots of fun to haveInHere.