unfortunately, this module needs to be inside the package, and it also needs to be runnable as a script, sometimes. Any idea how I could achieve that? It’s quite common to have a layout like this… main.py mypackage/ __init__.py mymodule.py myothermodule.py …with a mymodule.py like this… #!/usr/bin/env python3 # Exported function def as_int(a): return int(a) … Read more
The assert statement exists in almost every programming language. It has two main uses: It helps detect problems early in your program, where the cause is clear, rather than later when some other operation fails. A type error in Python, for example, can go through several layers of code before actually raising an Exception if … Read more
In Python, the ‘null’ object is the singleton None. To check if something is None, use the is identity operator: if foo is None: …
This information is available in the sys.version string in the sys module: >>> import sys Human readable: >>> print(sys.version) # parentheses necessary in python 3. 2.5.2 (r252:60911, Jul 31 2008, 17:28:52) [GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] For further processing, use sys.version_info or sys.hexversion: >>> sys.version_info (2, 5, 2, ‘final’, 0) # or >>> sys.hexversion 34014192 To … Read more
Script vs. Module Here’s an explanation. The short version is that there is a big difference between directly running a Python file, and importing that file from somewhere else. Just knowing what directory a file is in does not determine what package Python thinks it is in. That depends, additionally, on how you load the … Read more
Chaining comparison operators: >>> x = 5 >>> 1 < x < 10 True >>> 10 < x < 20 False >>> x < 10 < x*10 < 100 True >>> 10 > x <= 9 True >>> 5 == x > 4 True In case you’re thinking it’s doing 1 < x, which comes … Read more
One easy way would be to reassign the dataframe with a list of the columns, rearranged as needed. This is what you have now: In [6]: df Out[6]: 0 1 2 3 4 mean 0 0.445598 0.173835 0.343415 0.682252 0.582616 0.445543 1 0.881592 0.696942 0.702232 0.696724 0.373551 0.670208 2 0.662527 0.955193 0.131016 0.609548 0.804694 0.632596 … Read more
setup.py is a python file, the presence of which is an indication that the module/package you are about to install has likely been packaged and distributed with Distutils, which is the standard for distributing Python Modules. This allows you to easily install Python packages. Often it’s enough to write: $ pip install . pip will … Read more
To answer your first question… .format just seems more sophisticated in many ways. An annoying thing about % is also how it can either take a variable or a tuple. You’d think the following would always work: “Hello %s” % name yet, if name happens to be (1, 2, 3), it will throw a TypeError. … Read more
Use os.path.isdir for directories only: >>> import os >>> os.path.isdir(‘new_folder’) True Use os.path.exists for both files and directories: >>> import os >>> os.path.exists(os.path.join(os.getcwd(), ‘new_folder’, ‘file.txt’)) False Alternatively, you can use pathlib: >>> from pathlib import Path >>> Path(‘new_folder’).is_dir() True >>> (Path.cwd() / ‘new_folder”https://stackoverflow.com/”file.txt’).exists() False