ENH: Optimize nrows in read_excel #35974
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
WillAyd
reviewed
Sep 2, 2020
pandas/io/excel/_base.py
Outdated
| @@ -453,7 +491,20 @@ def parse( | |||
| else: # assume an integer if not a string | |||
| sheet = self.get_sheet_by_index(asheetname) | |||
|
|
|||
| data = self.get_sheet_data(sheet, convert_float) | |||
| get_sheet_data_header = 0 if header is None else header | |||
There was a problem hiding this comment.
Is this required? Looks like there are already checks within the subsequent functions for int values, no?
pandas/io/excel/_xlrd.py
Outdated
|
|
||
| for i in range(sheet_nrows): | ||
| if self.should_skip_row(i, header, skiprows, nrows): | ||
| data.append([]) |
There was a problem hiding this comment.
Do we need to append the empty list here? Would be preferable to just continue
There was a problem hiding this comment.
I removed should_skip_row entirely, I think the benefit from the original PR came from not reading all the rows into memory, rather than from optimising skipping rows
|
Performance benchmarks: The OP mentioned a memory leak from skipping rows in openpyxl, which I experienced too, so I've skipped optimising those files for now |
|
looks good, i thought this would make a much bigger difference, but ok. cc @WillAyd |
WillAyd
approved these changes
Sep 21, 2020
|
Thanks @MarcoGorelli |
| elif skiprows is None: | ||
| skiprows_nrows = 0 | ||
| else: | ||
| skiprows_nrows = len(skiprows) |
There was a problem hiding this comment.
this looks like its causing failures on master
There was a problem hiding this comment.
@jbrockmendel can you revert for now and we can reopen
jbrockmendel
added a commit
that referenced
this pull request
Sep 22, 2020
This reverts commit e975f3d.
|
@MarcoGorelli we are reverting this as something is broken in the evaluation here. If you can resubmit when you can. |
jreback
pushed a commit
that referenced
this pull request
Sep 22, 2020
|
Sure - I'm really sorry for the breakage caused, but glad this was caught early! |
kesmit13
pushed a commit
to kesmit13/pandas
that referenced
this pull request
Nov 2, 2020
kesmit13
pushed a commit
to kesmit13/pandas
that referenced
this pull request
Nov 2, 2020
…-dev#36537) This reverts commit e975f3d.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
black pandasgit diff upstream/master -u -- "*.py" | flake8 --diffbased on #33281
output of asv benchmarks: