[Tutor] reading stdin?

[Jörg Wölke]

> On Fri, Feb 16, 2001 at 01:17:32PM -0500, Mr 804 wrote:
> | 
> | how do I read stdin?
> | 
> 
> >>> data = raw_input( "Please give me some data: " )
> Please give me some data: Hello World
> >>> type( data )
> <type 'string'>
> >>> print data
> Hello World
> >>>
> 
> 
> raw_input is good if you want random stuff or text stuff,
> if you want other stuff, input can be helpful
> 
> >>> data = input( "Enter some data: " )
> Enter some data: 2
> >>> type( data )
> <type 'int'>
> >>> print data
> 2
> >>>
> 
> 
> However, be careful how you use input() :
> 
> >>> data = input( "Enter some data: " )
> Enter some data: foo
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "<string>", line 0, in ?
> NameError: There is no variable named 'foo'
> >>>
> 
> >>> i = 2
> >>> data = input( "Enter some data: " )
> Enter some data: lambda x : x + i
> >>> type( data )
> <type 'function'>
> >>> print data
> <function <lambda> at 007A8574>
> >>> print data( 3 )
> 5
> >>>
> 
> 
> input won't always do what you want, if the user inputs bad stuff.
> You can use raw_input, then convert the string how you want to.  Ex:
> 
> >>> try :
> ...     data = int( raw_input( "Enter a number: " ) )
> ... except ValueError , err :
> ...     print "You didn't enter a valid number"
> ...

excuse me if that's a silly question:
why not just
try:
     data = input("Enter number: ")
except:
     "wrong"

which would trap all errors?

greets jö!

> 
> 
> If you have more questions, just ask.
> 
> HTH,
> -D
> 
> 
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