BUG: Series.__setitem__ failing to cast numeric values

[jbrockmendel]

• closes #xxxx
• tests added / passed
• Ensure all linting tests pass, see here for how to run them
• whatsnew entry

Two cases this fixes (both tested in test_coersion)

ser = pd.Series([1, 2, 3, 4])
ser[1] = 1.1
>>> ser[1]
1.1  # <- PR
1    # <- master; note that setting with loc or iloc *does* cast


ser2 = pd.Series([1, 2, 3, 4], dtype=np.int8)
ser2[1] = np.int16(512)

>>> ser2[1]
512 # <- PR; casts to int16
0   # <- master; still np.int8; note that setting with with loc or iloc *does* cast

Downside: can_hold_element is heavier-weight than validate_numeric_casting.

[jreback]

this is a break with numpy (good) but needs a good note here

[phofl]

This adresses parts of #20643 I think. The Series.setitem case was not working there

[phofl]

Also:

• BUG: setting float on integer column with DataFrame.at casts the value to integer. #37477
• Cannot set value correctly #15413

[jreback]

@jbrockmendel addressing @phofl comments in followup or here?

[jbrockmendel]

Follwups. Definitely plural.

…

On Fri, Dec 31, 2021 at 6:58 AM Jeff Reback ***@***.***> wrote: @jbrockmendel <https://github.com/jbrockmendel> addressing @phofl <https://github.com/phofl> comments in followup or here? — Reply to this email directly, view it on GitHub <#45121 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB5UM6GFJPCM6JOUTFCZRRDUTXAIVANCNFSM5K65KHHQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[jreback]

k great