python不被识别为内部或外部命令

Question

This is a really annoying problem. I've prowled the web for solutions, but all I found was tips about changing the PATH variable, which I did, of course. My Python install directory is C:\\Python27. It' a 32 bit version. Whenever I type python in the command prompt, it says that it isn't recognised as an internal or external command. Currently, my PATH variable is set to C:\\Python27;C:\\Python27\\Lib\\site-packages\\;C:\\Python27\\Scripts. Anyone has any ideas? I run Windows 7 by the way (64 bit). I'm pretty desperate. Heck, if nothing works I guess I'll try dual-booting Linux and Windows 7...

Answer 1

Just adding the Python path and trying again worked for me (without reboot).

MS-dos command for Python 2.7:

set PATH=%PATH%;C:\python27\

MS-dos command for Python 3.3:

set PATH=%PATH%;C:\python33\

(check if that is the folder where you installed Python).

Answer 2

Quick fix: May not be the most elegant or long term fix but if you are really frustrated and just want to get it to run, just copy paste the python.exe file to your current directory. This worked for me.

Answer 3

After changing the PATH variable in windows, you need to reboot your system before it takes effect.

Edit: As stated by @tdelaney, only a restart of cmd.exe should be required. This is true atleast for Windows 7 64bit.

Answer 4

After adding the python folder to the system PATH variable, you should reboot your computer.

Another simple solution is: create a shortcut of the python.exe executable (probably it is in C:\\Python27\\python.exe , or similar) in a place like C:\\Windows\\system32 (that is, a place that already is listed in the PATH variable). The name of your shortcut should be python (maybe python.exe should work too). I mean, it can't be python - shortcut or similar, for your purposes.

To see the contents of the PATH variable, go to the cmd and enter set PATH .

Answer 5

In your PATH have you got a leading space before your Python path?

For example:

"C:\somedirectory\bin; C:\Python27;C:\Python27\Lib\site-packages\;C:\Python27\Scripts"

If you have a leading space between path's "ry\\bin; C:\\Pyt" , it won't work and is usually the cause for this type of issue.

Answer 6

When installing, there is a checkbox that is by default not selected, but it asks to add python to the environment variable. Re-install and check that box.

I'd rather the installer do it than struggle in the weeds myself.

Answer 7

好的，正如你说你的Python安装目录是C：\\ Python27，打开我的电脑，然后打开c：驱动器，如果你没有看到“Python27”命名文件夹，那么尝试使用搜索选项搜索它，（在我的情况下）我发现它在old.window文件夹中，不知道它是如何移动的那样）在c盘中剪切并将其与文件夹一样，程序文件，用户等...，现在打开cmd并键入python并按Enter键进行检查如果现在有效，

Answer 8

This is only a partial answer, but I found (repeatedly) that I'd have similar issues when I would use the gui installer and not go through the custom setup.

Using the custom setup option, then using the same settings, the "install for all users" (that then installs to C://python.version/blah instead of the user based default structure) WOULD allow the installer to setup PATH correctly.