Display help message with Python argparse when script is called without any arguments
Assume I have a program that uses argparse to process command line arguments/options. The following will print the ‘help’ message:
python
ValueError: math domain error
I was just testing an example from Numerical Methods in Engineering with Python.
Fastest save and load options for a numpy array
I have a script that generates two-dimensional numpy arrays with dtype=float and shape on the order of (1e3, 1e6). Right now I’m using np.save and np.load to perform IO operations with the arrays. However, these functions take several seconds for each array. Are there faster methods for saving and loading the entire arrays (i.e., without making assumptions about their contents and reducing them)? I’m open to converting the arrays to another type before saving as long as the data are retained exactly.
Using Counter() in Python to build histogram?
I saw on another question that I could use Counter() to count the number of occurrences in a set of strings. So if I have ['A','B','A','C','A','A'] I get Counter({'A':3,'B':1,'C':1}). But now, how can I use that information to build a histogram for example?
Python ascii utf unicode
When I parse this XML with p = xml.parsers.expat.ParserCreate():
Does the SVM in sklearn support incremental (online) learning?
I am currently in the process of designing a recommender system for text articles (a binary case of ‘interesting’ or ‘not interesting’). One of my specifications is that it should continuously update to changing trends.
re.sub(“.*”, “, “(replacement)”, “text”) doubles replacement on Python 3.7
On Python 3.7 (tested on Windows 64 bits), the replacement of a string using the RegEx .* gives the input string repeated twice!
Scope of variable within “with” statement?
I am reading only firstline from python using :
Valid characters in a python class name
I’m dynamically creating python classes, and I know not all characters are valid in this context.
Delete all data for a kind in Google App Engine
I would like to wipe out all data for a specific kind in Google App Engine. What is the
best way to do this?
I wrote a delete script (hack), but since there is so much data is
timeout’s out after a few hundred records.