Reading file involves concatenation at https://github.com/vkhodygo/am_tools/blob/643953aa1a92dac12b845ab02d45d5d3d0a5d3db/am_tools/modules/giant_density_fluctuations.py#L70 That behaviour is undesired as discussed here: [1](https://stackoverflow.com/questions/36489576/why-does-concatenation-of-dataframes-get-exponentially-slower/36489724) and [2](https://stackoverflow.com/questions/25216962/python-concatenation-vs-append-speed-on-lists) (see also [this](https://stackoverflow.com/questions/30245397/why-is-a-list-comprehension-so-much-faster-than-appending-to-a-list) discussion).
Reading file involves concatenation at
am_tools/am_tools/modules/giant_density_fluctuations.py
Line 70 in 643953a
That behaviour is undesired as discussed here: 1 and 2 (see also this discussion).