Column.get(map=) now returns dtype of labels

[hagenw]

Closes #400

As discussed in #400 (comment) when using audformat.Database.get() with the map argument, it should return the original dtype of the labels scheme (when using a misc table and a scheme is assigned to its corresponding column) or dtype should be inferred from the actual labels.

The example from #400

import audformat
import numpy as np
import pandas as pd

db = audformat.Database('db')
db.schemes['age'] = audformat.Scheme('int')

db['speaker'] = audformat.MiscTable(pd.Index(['s1', 's2'], dtype='string', name='speaker'))
db['speaker']['age'] = audformat.Column(scheme_id='age')
db['speaker']['age'].set([2, np.NaN])

db.schemes['speaker'] = audformat.Scheme('str', labels='speaker')

db['files'] = audformat.Table(audformat.filewise_index(['f1', 'f2']))
db['files']['speaker'] = audformat.Column(scheme_id='speaker')
db['files']['speaker'].set(['s1', 's2'])

db['files']['speaker'].get(map='age')

now returns

file
f1       2
f2    <NA>
Name: age, dtype: Int64

And the example from #317

db = audformat.Database('db')
db.schemes['text'] = audformat.Scheme(dtype='str')
db['misc'] = audformat.MiscTable(
    pd.Index(
      ['a', 'b', 'c'],
      name='speaker',
      dtype='string',
    )
)
db['misc']['text'] = audformat.Column(scheme_id='text')
db['misc']['text'].set(['A', 'B', 'C'])

db.schemes['scheme'] = audformat.Scheme('str', labels='misc')
db['table'] = audformat.MiscTable(audformat.filewise_index(['f1', 'f2', 'f3']))
db['table']['column'] = audformat.Column(scheme_id='scheme')
db['table']['column'].set(['a', 'b', 'c'])

db['table']['column'].get(map='text')

now returns

file
f1    A
f2    B
f3    C
Name: text, dtype: string

---

In order to use audformat.core.common.to_audformat_dtype(), I updated it to also handle the input coming from pd.api.types.infer_dtype() which is used to infer the dtype from a list of values.

[codecov]

Codecov Report

Merging #402 (89c59cc) into main (77f69bf) will not change coverage.
The diff coverage is 100.0%.

Files	Coverage Δ
audformat/core/column.py	100.0% <100.0%> (ø)
audformat/core/common.py	100.0% <100.0%> (ø)

[hagenw]

Handling of datetime and timedelta are still missing.

[hagenw]

Now, all dtypes we support in audformat are covered.