descriptor

问题 I want to be able use python descriptors in a class which has the slots optimization: class C(object): __slots__ = ['a'] a = MyDescriptor('a') def __init__(self, val): self.a = val The problem I have is how to implement the descriptor class in order to be able to store values in the class instance which invokes the descriptor object. The usual solution would look like the one below but will not work since "dict" is no longer defined when "slots" is invoked in the C class: class MyDescriptor

问题 This question already has answers here : Why dict.get(key) instead of dict[key]? (10 answers) Closed 4 years ago . Why does this throw a KeyError: d = dict() d['xyz'] But this does not? d = dict() d.get('xyz') I'm also curious if descriptors play a role here. 回答1: This is simply how the get() method is defined. From the Python docs: Return the value for key if key is in the dictionary, else default. If default is not given, it defaults to None, so that this method never raises a KeyError. The

问题 I just updated my Eclipse from Galileo to Juno. I created a new workspace and imported a Java Spring MVC based project. When I open it, it begins 'Loading descriptor' and then an error message pops up: An internal error occurred during: "Loading descriptor for mta_pfm.". If I open it using Galileo, there is no error. I tried to disable the validation of XML file in Juno, but it does not work. I have no idea how to fix it now. Please help. Thanks org.eclipse.emf.ecore.resource.impl

问题 I just updated my Eclipse from Galileo to Juno. I created a new workspace and imported a Java Spring MVC based project. When I open it, it begins 'Loading descriptor' and then an error message pops up: An internal error occurred during: "Loading descriptor for mta_pfm.". If I open it using Galileo, there is no error. I tried to disable the validation of XML file in Juno, but it does not work. I have no idea how to fix it now. Please help. Thanks org.eclipse.emf.ecore.resource.impl

问题 I'm really new to A-Frame and Ar.js, literally found out about this and started working on this today. It's for a project I'm doing and I'm using this tutorial https://aframe.io/blog/arjs3/#creating-image-descriptors I followed the instructions and uploaded the 'dinosaur' image into an NFT creator. It said I would get three images downloaded, I did and they end with fset3, fset and iset. I tried clicking on the downloaded images and got a message saying 'There is no application set to open

问题 I'm really new to A-Frame and Ar.js, literally found out about this and started working on this today. It's for a project I'm doing and I'm using this tutorial https://aframe.io/blog/arjs3/#creating-image-descriptors I followed the instructions and uploaded the 'dinosaur' image into an NFT creator. It said I would get three images downloaded, I did and they end with fset3, fset and iset. I tried clicking on the downloaded images and got a message saying 'There is no application set to open

来源： https://stackoverflow.com/questions/27068673/subscribe-to-a-ble-gatt-notification-android

问题 I have a structure with different datatype fields. I would like to iterate through the structure fields, check the datatype, and set the field with an appropriate value. I have access to the size and offset of the field through the .size and .offset attribute of the field. How can I get the 'type' attribute of the field? Using type(value) does not print the ctypes datatype for the particular field. If I print value then I do see the ctypes datatype but there doesn't seem to be an attribute to

问题 I have a structure with different datatype fields. I would like to iterate through the structure fields, check the datatype, and set the field with an appropriate value. I have access to the size and offset of the field through the .size and .offset attribute of the field. How can I get the 'type' attribute of the field? Using type(value) does not print the ctypes datatype for the particular field. If I print value then I do see the ctypes datatype but there doesn't seem to be an attribute to

问题 I have a structure with different datatype fields. I would like to iterate through the structure fields, check the datatype, and set the field with an appropriate value. I have access to the size and offset of the field through the .size and .offset attribute of the field. How can I get the 'type' attribute of the field? Using type(value) does not print the ctypes datatype for the particular field. If I print value then I do see the ctypes datatype but there doesn't seem to be an attribute to