Running the following codes
with open('abc', 'wt') as fh:
fh.write('\n'.join(['a','b','c']))
in ipython, no outputs as expected;
however, in jupyter notebook, output like [Out 4]: 5.
It's possibly related to
from IPython.core.interactiveshell import InteractiveShell
InteractiveShell.ast_node_interactivity = "all"
in jupyter. But what's the strange thing jupyter output and how to prevent?
I'm not familiar with jupyter, but if it's a REPL that prints the results of expressions as they're evaluated, it's printing the return value of fh.write. write returns the numbers of characters written, so that's being printed out.
_ = fh.write prevents the output because = is a statement that does not evaluate to a value. You may also be able to prevent the output by doing something like fh.write(...); None. I wouldn't recommend doing this in real code, but for the sake of limiting output, it may be beneficial.
