In this case, it opens a text file. It also has to return the descriptor of the resource, so it returns the opened file. The as file assigns the file to a variable file. Finally, the code you want to run with the acquired resource is placed in the with block after the colon. As...
Put very simply, a descriptor is a class that can be used to call a method with simple dot notation, also referred to as attribute access, but there’s obviously more to it than that. It’s difficult to really explain beyond that without digging a little into how they’re implemented. ...
Whenever a function is accessed as an attribute, the descriptor is invoked, creating a method object which "binds" the function with the object owning the attribute. If called, the method calls the function, implicitly passing the bound object as the first argument (this is how we get self ...
A new way to edit your Python formulas Today we are excited to announce that the Python Editor is rolling out and will be generally available for Current Channel Windows users starting with 16.0.18... By the way, are there any plans to add AFE in more native way? Keyboard Shortcut \n...
Last week, while working on a support case, our customer was facing performance issues in their Python application. After some investigation, I decided to...
File "<stdin>", line 1, in <module> TypeError: descriptor '__len__' requires a 'str' object but received a 'list' >>from operator import attrgetter >>sorted(seq, key=attrgetter( "__len__")) ['aaaa', 'bb', 'c', 'ddd'] >>sorted(seq2 , key=attrgetter( "__len__")) ...
While Python provides a C API for thread-local storage support; the existing Thread Local Storage (TLS) API has used int to represent TLS keys across all platforms. This has not generally been a problem for officially-support platforms, but that is neither POSIX-compliant, nor portable in any...
The io.FileIO class now raises an OSError when passed an invalid file descriptor. (Implemented by Benjamin Peterson; bpo-4991.) The truncate() method now preserves the file position; previously it would change the file position to the end of the new file. (Fixed by Pascal Chambon; bpo-...
In the other cases, we’ll have errors.A general rule of thumb is to always define functions, variables, objects and classes before using them, to avoid surprises.Suppose we have a function:function bark() { alert('wof!') }Due to hoisting, we can technically invoke bark() before it ...
What is a file descriptor used in Python? What is a sequence data type in Python? What is the difference between a python module and a python package? What is Python, and what is it used for? What is a Python module? How is it different from libraries? What is immutable in Python?