Michael Connors wrote:
2009/8/6 Joshua Harper <joshharpe...@gmail.com>
Ok, so I am trying to learn python, and I am reading many tutorial type
things and I am kind of stuck with implementing some of the code... so for
example the tutorial says "*To get the examples working properly, write
the programs in a text file and then run that with the interpreter*"
Alright...simple enough so I wirte the example program:
x = input("Please enter a number: ")
print "The square of that number is
I save this as a .py and Open With>python.exe. OK, so that gives me the
terminal ansking me to enter a number, I enter a number and click enter and
then it prints in like half a nanosecond and the cmd line window closes. I
want to know how to have the window stay open so that, in future scripts I
may be able to actually see what was printed. I talked to my friend and he
said that he has the same problem...anybody?...help???
It closes because it is finished.
If you want to see the result, you could either:
- Place another input("") after the print statement.
- Run the program from the command prompt (in which case you will probably
need to set the path)
Michael is correct, but I'd like to expand on the answer.
In Windows, there are two kinds of applications, console apps and gui
apps. A console app uses stdin and stdout (character mode, like input
and print). A gui app has buttons, menus, and dialog boxes. Console
apps are much easier to write and debug, they tend to run faster, and
tutorials always start there.
A console app can be run from an Explorer shortcut, or from the context
menu as you're doing, but you're missing a lot. As you've already
noticed, the console is deleted immediately after the program
terminates. So you can put an extra input("Press OK to finish") at
the end of your code. But for various reasons (eg. bugs) your program
may never reach that line. And if it doesn't, any error messages will
also vanish when the console does. While there are workarounds for
this, the real answer is to learn to use a command prompt. At least
until a program is bug-free.
A "command prompt" (aka "Dos Box", or console, or shell) can be started
from the "Run" command on the start menu -- just type "Cmd" as the
program to run. There's also a shortcut called "Command Prompt" in
Start->Accesssories.
The default installation on Windows sets up a file association for both
.py and .pyw files, so you should be able to just type example.py
at the command prompt to run the program. The command prompt window
will scroll to hold more input than would otherwise fit on screen. And
you can copy & paste from and to a command prompt, though it's tricky
(another discussion).
You may want to create a few batch files to make your life at the
command prompt a bit easier. For example, the path to the python
interpreter is not normally added to the PATH variable, and I don't
think it should. So if you want to run Python.exe explicitly, it helps
to make a batch file to make that easier. We can help with that as well.
When you run the program from the command prompt, the print output stays
there till you either close the command prompt, or run enough other
stuff that it scrolls off the top end of the buffer.
DaveA
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