How do I melt a pandas dataframe?
On the pandas tag, I often see users asking questions about melting dataframes in pandas. I am gonna attempt a cannonical Q&A (self-answer) with this topic.
python
How do I expand the output display to see more columns of a Pandas DataFrame?
Is there a way to widen the display of output in either interactive or script-execution mode?
What is the formal difference between “print” and “return”?
printAndReturn will return x to the caller of the method, so:
Python’s many ways of string formatting — are the older ones (going to be) deprecated?
Python has at least six ways of formatting a string:
Can scrapy be used to scrape dynamic content from websites that are using AJAX?
I have recently been learning Python and am dipping my hand into building a web-scraper. It’s nothing fancy at all; its only purpose is to get the data off of a betting website and have this data put into Excel.
How to delete a specific line in a file?
Let’s say I have a text file full of nicknames. How can I delete a specific nickname from this file, using Python?
Use a list of values to select rows from a Pandas dataframe
Let’s say I have the following Pandas dataframe:
Permanently add a directory to PYTHONPATH?
Whenever I use sys.path.append, the new directory will be added. However, once I close python, the list will revert to the previous (default?) values. How do I permanently add a directory to PYTHONPATH?
Are list-comprehensions and functional functions faster than “for loops”?
In terms of performance in Python, is a list-comprehension, or functions like map(), filter() and reduce() faster than a for loop? Why, technically, they run in a C speed, while the for loop runs in the python virtual machine speed?.
How to input a regex in string.replace?
I need some help on declaring a regex. My inputs are like the following: