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.
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: ...