pythonw.exe 还是 python.exe？

Question

Long story short: pythonw.exe does nothing, python.exe accepts nothing (which one should I use?)

test.py:

print "a"

CMD window:

C:\path>pythonw.exe test.py
<BLANK LINE>
C:\path>

C:\path>python.exe test.py
  File "C:\path\test.py", line 7
    print "a"
            ^
SyntaxError: invalid syntax

C:\path>

Please tell me what I'm doing terrible wrong.

Answer 1

To summarize and complement the existing answers:

• python.exe is a console (terminal) application for launching CLI-type scripts (console applications) .

  • Unless run from an existing console window, python.exe opens a new console window .

  • Standard streams sys.stdin , sys.stdout and sys.stderr are connected to the console window .

  • Execution is synchronous when launched from a cmd.exe or PowerShell console window: ^{See eryksun 's 1st comment below.}

    • If a new console window was created, it stays open until the script terminates.
    • When invoked from an existing console window, the prompt is blocked until the script terminates.

• pythonw.exe is a GUI app for launching GUI/no-UI-at-all scripts .

  • NO console window is opened.
  • Execution is asynchronous :
    • When invoked from a console window, the script is merely launched and the prompt returns right away, whether the script is still running or not.
  • Standard streams sys.stdin , sys.stdout and sys.stderr are NOT available .
    • Caution : Unless you take extra steps , this has potentially unexpected side effects :
      • Unhandled exceptions cause the script to abort silently .
      • In Python 2.x, simply trying to use print() can cause that to happen (in 3.x, print() simply has no effect).
        • To prevent that from within your script , and to learn more, see this answer of mine.
        • Ad-hoc , you can use output redirection : ^{Thanks, @handle.}
          pythonw.exe yourScript.pyw 1>stdout.txt 2>stderr.txt
          (from PowerShell:
          cmd /c pythonw.exe yourScript.pyw 1>stdout.txt 2>stderr.txt ) to capture stdout and stderr output in files .
          If you're confident that use of print() is the only reason your script fails silently with pythonw.exe , and you're not interested in stdout output, use @handle's command from the comments:
          pythonw.exe yourScript.pyw 1>NUL 2>&1
          Caveat : This output redirection technique does not work when invoking *.pyw scripts directly (as opposed to by passing the script file path to pythonw.exe ). ^{See eryksun 's 2nd comment and its follow-ups below.}

---

You can control which of the executables runs your script by default - such as when opened from Explorer - by choosing the right filename extension :

• *.py files are by default associated (invoked) with python.exe
• *.pyw files are by default associated (invoked) with pythonw.exe

Answer 2

If you don't want a terminal window to pop up when you run your program, use pythonw.exe ;
Otherwise, use python.exe

Regarding the syntax error: print is now a function in 3.x
So use instead:

print("a")

Answer 3

See here: http://docs.python.org/using/windows.html

pythonw.exe "This suppresses the terminal window on startup."

Answer 4

If you're going to call a python script from some other process (say, from the command line), use pythonw.exe . Otherwise, your user will continuously see a cmd window launching the python process. It'll still run your script just the same, but it won't intrude on the user experience.

An example might be sending an email; python.exe will pop up a CLI window, send the email, then close the window. It'll appear as a quick flash, and can be considered somewhat annoying. pythonw.exe avoids this, but still sends the email.

Answer 5

I was struggling to get this to work for a while. Once you change the extension to .pyw, make sure that you open properties of the file and direct the "open with" path to pythonw.exe.

Answer 6

根据我的经验，pythonw.exe 至少在使用 pygame 时更快。