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Improve accuracy. In the .tex file, note the new "% BUG:" comments: an 

extra backslash is getting displayed in the generated HTML.
This commit is contained in:
Tim Peters 2001-02-20 11:24:35 +00:00
parent f0768c822b
commit 754ba589b7
2 changed files with 15 additions and 10 deletions
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19
Doc/lib/libdifflib.tex
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@ -53,8 +53,8 @@
\strong{Timing:} The basic Ratcliff-Obershelp algorithm is cubic
time in the worst case and quadratic time in the expected case.
\class{SequenceMatcher} is quadratic time for the worst case and has
expected-case behavior dependent on how many elements the sequences
have in common; best case time (no elements in common) is linear.
expected-case behavior dependent in a complicated way on how many
elements the sequences have in common; best case time is linear.
\end{classdesc}
@ -68,6 +68,9 @@
\code{None} is equivalent to passing \code{lambda x: 0}, i.e.\ no
elements are ignored. For example, pass
% BUG: the HTML generated for this is
% BUG: lambda x: x in " \\t"
% BUG: i.e. it displays two backslashes.
\begin{verbatim}
lambda x: x in " \\t"
\end{verbatim}
@ -138,7 +141,7 @@ of the other sequences.
junk happens to be adjacent to an interesting match.
Here's the same example as before, but considering blanks to be junk.
That prevents \code{' abcd'} from matching the \code{ abcd} at the
That prevents \code{' abcd'} from matching the \code{' abcd'} at the
tail end of the second sequence directly. Instead only the
\code{'abcd'} can match, and matches the leftmost \code{'abcd'} in
the second sequence:
@ -217,8 +220,8 @@ replace a[3:4] (x) b[2:3] (y)
range [0, 1].
Where T is the total number of elements in both sequences, and M is
the number of matches, this is 2,0*M / T. Note that this is \code{1}
if the sequences are identical, and \code{0} if they have nothing in
the number of matches, this is 2.0*M / T. Note that this is \code{1.}
if the sequences are identical, and \code{0.} if they have nothing in
common.
This is expensive to compute if \method{get_matching_blocks()} or
@ -242,8 +245,10 @@ replace a[3:4] (x) b[2:3] (y)
\method{ratio()} or \method{quick_ratio()}.
\end{methoddesc}
The three methods that return the ratio of differences to similarities
can give different results due to differing levels of approximation:
The three methods that return the ratio of matching to total characters
can give different results due to differing levels of approximation,
although \method{quick_ratio()} and \method{real_quick_ratio()} are always
at least as large as \method{ratio()}:
\begin{verbatim}
>>> s = SequenceMatcher(None, "abcd", "bcde")

6
Lib/difflib.py
View File

@ -92,9 +92,9 @@ See also function get_close_matches() in this module, which shows how
simple code building on SequenceMatcher can be used to do useful work.
Timing: Basic R-O is cubic time worst case and quadratic time expected
case. SequenceMatcher is quadratic time worst case and has expected-case
behavior dependent on how many elements the sequences have in common; best
case time (no elements in common) is linear.
case. SequenceMatcher is quadratic time for the worst case and has
expected-case behavior dependent in a complicated way on how many
elements the sequences have in common; best case time is linear.
SequenceMatcher methods: