fix typo in variable name (closes #21586)
merge 3.4 (#21586)
remove tab (closes #21587)
merge 3.4 (#21587)
oxford comma
link to wikipedia description of cryptographic salt
merge 3.4
format reST directive in the usual way
merge 3.4
grammar and sentence flow fix
merge 3.4
a post 3.4.1 world
null merge 3.4
Minor clean-ups for heapq.merge().
Issue 21575:  Show list.sort() arguments in the tutorial.
Issue 21439:  Minor issues in the reference manual.

(Contributed by Feliks Kluzniak.)
merge