Python Programming On Win32

Using the Windows Command Prompt

Both the Windows 95/98 and NT/2000 families come with a command prompt allowing users to run programs from a command-line interface. The Windows command prompt has a long and not-so-glorious history; it has grown from the first versions of MS-DOS and still uses the same basic syntax.

Running Python programs

For these discussions, let’s assume you have a file named C:\Scripts\hello.py, and this file consists of the single line:

print "Hello from Python"

A first attempt to run this program may surprise you:

C:\Scripts>python.exe hello.py
The name specified is not recognized as an
internal or external command, operable program or batch file.

C:\Scripts>

Although Python.exe has been installed, it hasn’t modified the system environment variable PATH: Windows doesn’t know how to find Python.exe. Windows NT does, however, know how to run .py files directly. Thus, if you ask the command prompt to execute hello.py, it will:

C:\Scripts>hello.py
Hello from Python

C:\Scripts>

Take this one step further and avoid the use of the .py extension, making a Python program appear like a .exe, .com, or .bat file. Windows NT supports this using the PATHEXT environment variable. You can view the current settings of this variable by entering the command:

C:\Scripts>echo %PATHEXT%
.exe;.bat;.cmd

C:\Scripts>

This is a list of the default extensions Windows searches for when a command is executed. You can add Python files to this list (and check the change was successful) by executing: ...