I have a specific matrix with dimensions (nz,ny,nx) and another matrix with dimensions (ny,nx). In this other matrix are specific values and for instance I want to sum all the points in this first 3-dimensional matrix at locations where the second matrix has a specific value. I am doing the following: which h…
Tag: python
I am getting ValueError: invalid literal for int() with base 10 with np.where function
I want to change ‘not available’ value in a df column into 0, and for the rest of the values to change them into integers. Unique values in the column are: I run the following code to change values to integers: I expect that the above would turn all values into integers, yet I get the value error …
pandas shift on condition of a column isnull but it removes the first two columns
I have this problem with shifting an entire row based on a column condition if it is NaN. if column 10 is NaN, shift the entire row 3 cells to the right. initial dataframe: I come up with this solution, but the first two columns are gone somehow. df1_copy[df1_copy[10].isnull()] = df1_copy[df1_copy[10].isnull(…
How to trim (crop) bottom whitespace of a PDF document, in memory
I am using wkhtmltopdf to render a (Django-templated) HTML document to a single-page PDF file. I would like to either render it immediately with the correct height (which I’ve failed to do so far) or render it incorrectly and trim it. I’m using Python. Attempt type 1: wkhtmltopdf render to a very,…
Ordering a two-dimensional array relative to the main diagonal
Given a two-dimensional array T of size NxN, filled with various natural numbers (They do not have to be sorted in any way as in the example below.). My task is to write a program that transforms the array in such a way that all elements lying above the main diagonal are larger than each element lying on the …
How do I check the existing file with same name in the directory and use python to rename new files to save?
I am using plt.savefig to save a plot generated by matplotlib.pyplot, and I want to save my figure with different names each time I run the code. How can I do that? Answer The easiest would probably be to use the current time, if you don’t save multiple files per second.
Python type hint for Iterable[str] that isn’t str
In Python, is there a way to distinguish between strings and other iterables of strings? A str is valid as an Iterable[str] type, but that may not be the correct input for a function. For example, in this trivial example that is intended to operate on sequences of filenames: Passing in a single filename would…
How to delete a certain value in a cell in columns of csv using pandas
I need help with deleting “None” along with extra comma in language columns that have one or more language Here is the existing csv: Where f now looks like: And the result should be like this: There are also other columns that have only ‘None’ values in language column, so I can’…
Altair combine two charts
I am trying to plot/combine two charts on Altair, but only one of the chart is actually showing with the expected data. The second chart doesn’t show. The second chart is blank Code below: Image below: Answer If life is referring to life expectancy, the reason you don’t see the lines is the lower …
Most efficient way of applying a function based on condition
Suppose we have a master dictionary master_dict = {“a”: df1, “b”: df2, “c”: df3}. Now suppose we have a list called condition_list. Suppose func is a function that returns a new dictionary that has the original keys of master_dict along with potentially new keys. What is th…