Syntax error on print with Python 3 [duplicate]
In Python 3, print became a function. This means that you need to include parenthesis now like mentioned below: print(“Hello World”)
python-3.x
Unable to set default python version to python3 in ubuntu
The second line mentioned can be changed to [sudo] update-alternatives –install /usr/bin/python python /usr/bin/python3 10 This gives a priority of 10 for the path of python3. The disadvantage of alternatively editing .bashrc is that using the commands with sudo will not work.
PyLint message: logging-format-interpolation
It is not true for logger statement because it relies on former “%” format like string to provide lazy interpolation of this string using extra arguments given to the logger call. For instance instead of doing: logger.error(‘oops caused by %s’ % exc) you should do logger.error(‘oops caused by %s’, exc) so the string will only … Read more
How do I change the string representation of a Python class? [duplicate]
The closest equivalent to Java’s toString is to implement __str__ for your class. Put this in your class definition: def __str__(self): return “foo” You may also want to implement __repr__ to aid in debugging. See here for more information: Special Method Names – Basic Customization
builtins.TypeError: must be str, not bytes
The outfile should be in binary mode. outFile = open(‘output.xml’, ‘wb’)
How to uninstall a package installed with pip install –user
Having tested this using Python 3.5 and pip 7.1.2 on Linux, the situation appears to be this: pip install –user somepackage installs to $HOME/.local, and uninstalling it does work using pip uninstall somepackage. This is true whether or not somepackage is also installed system-wide at the same time. If the package is installed at both … Read more
Why is ‘x’ in (‘x’,) faster than ‘x’ == ‘x’?
As I mentioned to David Wolever, there’s more to this than meets the eye; both methods dispatch to is; you can prove this by doing min(Timer(“x == x”, setup=”x = ‘a’ * 1000000″).repeat(10, 10000)) #>>> 0.00045456900261342525 min(Timer(“x == y”, setup=”x = ‘a’ * 1000000; y = ‘a’ * 1000000″).repeat(10, 10000)) #>>> 0.5256857610074803 The first can … Read more
Django MEDIA_URL and MEDIA_ROOT
UPDATE for Django >= 1.7 Per Django 2.1 documentation: Serving files uploaded by a user during development from django.conf import settings from django.conf.urls.static import static urlpatterns = patterns(”, # … the rest of your URLconf goes here … ) + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT) You no longer need if settings.DEBUG as Django will handle ensuring this is … Read more
How does asyncio actually work?
How does asyncio work? Before answering this question we need to understand a few base terms, skip these if you already know any of them. Generators Generators are objects that allow us to suspend the execution of a python function. User curated generators are implement using the keyword yield. By creating a normal function containing … Read more
Is generator.next() visible in Python 3?
[*] g.next() has been renamed to g.__next__(). The reason for this is consistency: special methods like __init__() and __del__() all have double underscores (or “dunder” in the current vernacular), and .next() was one of the few exceptions to that rule. This was fixed in Python 3.0. [*] But instead of calling g.__next__(), use next(g). [*] … Read more