BUG: bug in setitem where type promotion is applied to entire block

[behzadnouri]

closes #10280

on master:

>>> df
   foo  bar  baz
a    0    1    2
b    3    4    5
>>> df.dtypes
foo    int64
bar    int64
baz    int64
dtype: object
>>> df.loc['a', 'bar'] = 3.14
>>> df.dtypes
foo    float64
bar    float64
baz    float64
dtype: object

on branch:

>>> df.dtypes
foo    int64
bar    int64
baz    int64
dtype: object
>>> df.loc['a', 'bar'] = 3.14
>>> df.dtypes
foo      int64
bar    float64
baz      int64
dtype: object
>>> df
   foo   bar  baz
a    0  3.14    2
b    3  4.00    5

[jreback]

can you add some additonal tests (these should already work), for separation of other blocks types, e.g. object->float, float->object).

[jreback]

can you update

[behzadnouri]

i added more tests

[jreback]

ok thanks. ping when green

[behzadnouri]

a HTTPError: HTTP Error 404: Not Found error; otherwise all green

[jreback]

thanks!