This GitPro page does summarize the consequence of a git submodule update nicely When you run git submodule update, it checks out the specific version of the project, but not within a branch. This is called having a detached head — it means the HEAD file points directly to a commit, not to a symbolic … Read more
If you know what the Collatz conjecture is, I’m trying to make a calculator for that. I want to have x as my input so I don’t have to change x’s number and save every time I want to try out a new number. I get below error TypeError: not all arguments converted during string … Read more
As it is, both dimensions of your vector are 0. Instead, initialize the vector as this: This will give you a matrix of dimensions RR * CC with all elements set to 0.
The column names (which are strings) cannot be sliced in the manner you tried. Here you have a couple of options. If you know from context which variables you want to slice out, you can just return a view of only those columns by passing a list into the __getitem__ syntax (the []’s). Alternatively, if … Read more
No. Regular expressions in Python are handled by the re module. In general:
If you don’t want to worry about speed (and with 155 columns you probably don’t care) you can use the t.test function and apply it to every column. Simulate some data first Then we can apply the t.test function to all but the first column using the formula argument. which returns the test statistic for … Read more
Usually, a Python dictionary throws a KeyError if you try to get an item with a key that is not currently in the dictionary. The defaultdict in contrast will simply create any items that you try to access (provided of course they do not exist yet). To create such a “default” item, it calls the … Read more
Yes, it was added in version 2.5. The expression syntax is: First condition is evaluated, then exactly one of either a or b is evaluated and returned based on the Boolean value of condition. If condition evaluates to True, then a is evaluated and returned but b is ignored, or else when b is evaluated … Read more
Here’s an answer to the same question you’re asking: https://stackoverflow.com/a/2866456/4380308 Or you can use the ‘timeit’ module: https://stackoverflow.com/a/2866460/4380308
A context free grammar is a grammar which satisfies certain properties. In computer science, grammars describe languages; specifically, they describe formal languages. A formal language is just a set (mathematical term for a collection of objects) of strings (sequences of symbols… very similar to the programming usage of the word “string”). A simple example of … Read more