BUG: inconsistent and undocumented option "converters" to read_excel

[iosonofabio]

Issue #8212 (first part): pandas.read_excel accepts an optional argument "converters" (which is passed down to PythonParser) to convert single cells in columns with a conversion function. I documented this feature and added a try/except block to make it work in case some cells contain NaNs.

What's still missing is the full "dtype" argument, a la read_csv. That patch is somewhat orthogonal because it only works with the C parser, so I plan to implement it in a second step.

[jreback]

usually start off a PR with tests first.

[iosonofabio]

I added a test for this functionality.

[jreback]

ok, this looks fine

• need a release note in v0.15.0 (refere the issue you highlited above). as you are now allowing the converters argument to work with missing values. maybe adjust the docs a bit in doc/source/io.rst (excel section).

[iosonofabio]

I added some docs there, not sure it's enough, open for feedback.

[jreback]

take this line out (it has existed previously, just not documented)

[iosonofabio]

Hi, what's the current status on this? I think I implemented all you requested, do you think it's ready and can be merged?
No pressure, I am just trying to join loose ends...

[jreback]

take out the sentence starting with 'Lambda function'; its uncessary. Can you make this a bit more concise?

[jreback]

ok, pls edit the docs a bit, rebase and squash.

[iosonofabio]

Ok, edited docs, squashed, rebased, pushed (d0597b8).

[jreback]

instead of this, I think just expand the doc-string (just a bit, maybe 1 line) for TextReader and Excel (to make them consistent). This is also true more generally for csv-type reading, so don't want it specifically here.

[iosonofabio]

I am sorry, could you please reformulate? I can't understand.

1. What do you want to delete from the docs? I thought you wanted to have the ..note, or shall I delete the whole thing again?
2. Which line do you want to add to those docstrings? Could you please write here the line you want?
3. TextReader? or TextParser?
4. What is true more generally?
   Thanks.

edit: I tried to implement what I understood of your suggestion, please check and let me know.

[jreback]

this is good

[jreback]

looks ok to me

@jorisvandenbossche ?

[jorisvandenbossche]

Thanks!

[iosonofabio]

Thanks! I'm happy since it's my first PR and I made a bit of a mess. I'll try to work on the full dtype integration, using the C parser.