Tracemalloc's format documentation (https://docs.python.org/3/library/tracemalloc.html#tracemalloc.Traceback.format) says first:

"Format the traceback as a list of lines with newlines."

then:

"Similar to the traceback.format_tb() function, except that format() does not include newlines."

The first statement is incorrect, tracemalloc does NOT add newlines to the list. I recommend just removing the "with newlines" in the first statement.