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pythonnumpydebuggingpycharm

Display of large 1D numpy array in Pycharm debugger

I noticed something while debugging a Python program in Pycharm. I work with a large numpy 1D array of shape (n,). When looking at it via the variables tab in the PyCharm debugger, the values are displayed in a big row, space separated, but for every 18 values, there is a comma. I joined a picture of the debugger's output, but it just shows what I just said - at least I think it shows this: Output of the variable tab for my "sum_exp" array

This happens when debugging the following code snippet:

import numpy as np

a = np.full((19,), 10.0)
b = [ 10.0 for x in range(19)]
# line to be able to see a and b in the debugger before the end of the program
print()

The used version is Pycharm 2023.2.1.

If I look at a Python array of the same size, the separator is a coma and is used consistently in the whole array. I cannot test it on another computer to see if this is related to how it is stored in my memory.

My question is, why does this comma appear?

Solution

  • It appears to be related to how the variables are printed. If you run print(a), you will have a line break after 18 values. print(b) will simply print everything on a single line.

    You can change the behavior of numpy by setting the linewidth, e.g. to infinite as follows:

    np.set_printoptions(linewidth=np.inf)

    This will change the appearance a in the PyCharm debugger with the commas now removed.