当从命令提示符运行脚本时，不能将PiCamera初始化为类成员 [英] PiCamera cannot be initialized as a class member when the script is run from command prompt
问题描述
在我的树莓派，我遇到一个奇怪的行为，使用PiCamera模块。
on my Raspberry Pi, I encounter a strange behaviour regarding the use of the PiCamera module.
当从IDLE（F5）或从命令提示符（$ python test.py）启动时，以下代码运行顺畅
The following code runs smoothly when either started from IDLE (F5) or from the command prompt ($python test.py)
import picamera
if __name__ == "__main__":
camera=picamera.PiCamera()
camera.close()
但是当我把camera对象放到类中时，代码将只在从IDLE （F5）：
But when I put the camera object into a class the code will run only when started from IDLE (F5):
import picamera
class VF:
def __init__(self):
self.camera = picamera.PiCamera()
def __del__(self):
self.camera.close()
if __name__ == "__main__":
myvf = VF()
从命令提示符上面的代码，我得到以下错误消息：
When I start the above code from the command prompt, I get the following error message:
mmal：mmal_vc_component_enable：无法启用组件：ENOSPC
mmal: mmal_vc_component_enable: failed to enable component: ENOSPC
跟踪（最近一次调用）：文件test.py，第14行，在
myvf = VF（）
Traceback (most recent call last): File "test.py", line 14, in myvf = VF()
在 init 中的文件test.py第6行：
self.camera = picamera.PiCamera（）
File "test.py", line 6, in init self.camera = picamera.PiCamera()
文件/usr/lib/python2.7/dist-packages/picamera/camera.py，行
379，在 init
camera_num中， self.STEREO_MODES [stereo_mode]，stereo_decimate）
File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 379, in init camera_num, self.STEREO_MODES[stereo_mode], stereo_decimate)
文件/usr/lib/python2.7/dist-packages/picamera/camera.py，行
505，in _init_camera
prefix =Camera component could not be enabled）
File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 505, in _init_camera prefix="Camera component couldn't be enabled")
文件/usr/lib/python2.7/dist-packages /picamera/exc.py，第133行，
in mmal_check
raise PiCameraMMALError（status，prefix）
File "/usr/lib/python2.7/dist-packages/picamera/exc.py", line 133, in mmal_check raise PiCameraMMALError(status, prefix)
picamera.exc.PiCameraMMALError：Camera组件无法启用：
缺少资源（内存除外）
picamera.exc.PiCameraMMALError: Camera component couldn't be enabled: Out of resources (other than memory)
相机模块工作正常，I只是把代码下降到最小的可能的大小。有人知道这个问题，或类似的问题，并可能提供一个解决方案？ Python版本是2.7，Raspberry Rasbiab系统是完全最新的。
提前感谢。
The camera module is working correct, I just stripped the code down to the least possible size. Does anybody know this problem, or a similar problem, and can probably provide a solution? The Python Version is 2.7 and the Raspberry Rasbiab-System is completely up to date. Thanks in advance.
推荐答案
发现，当析构函数是没有明确调用（LED已关闭，因此没有看到这个）。
Found out, that the camera-module is not properly shut down when the destructor is not explicitly called (had LED turned off, so didn't see this).
IDLE通过某种方式在脚本启动之前重置它，而不是python解释器。
IDLE handles a running camera by somehow resetting it before the script starts, but not the python interpreter.
现在当脚本结束之前调用析构函数时一切正常。
So everything is ok now when the destructor is called before the script ends.
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