DataFrame constructor converts uint64 series to object series

[hrichardlee]

Code Sample, a copy-pastable example if possible

import pandas as pd
import numpy as np

uint64s = pd.Series([9710005220884355087, 9710005220138399309], dtype=np.dtype('uint64'))
uint64s.dtype  # dtype('uint64')

df = pd.DataFrame({'viadict': uint64s})
df['viacolumn'] = uint64s

df.info()
# Data columns (total 2 columns):
# viadict      2 non-null object
# viacolumn    2 non-null uint64

Problem description

It seems like these ways of adding columns to a dataframe should have the same behavior.

Expected Output

df.info()
# Data columns (total 2 columns):
# viadict      2 non-null uint64
# viacolumn    2 non-null uint64

(i.e. both columns are uint64s)

Output of pd.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 3.5.2.final.0 python-bits: 64 OS: Windows OS-release: 7 machine: AMD64 processor: Intel64 Family 6 Model 45 Stepping 7, GenuineIntel byteorder: little LC_ALL: None LANG: None pandas: 0.18.1 nose: 1.3.7 pip: 9.0.1 setuptools: 27.2.0 Cython: 0.25.1 numpy: 1.11.1 scipy: 0.18.0 statsmodels: 0.6.1 xarray: None IPython: 5.1.0 sphinx: 1.4.1 patsy: 0.4.1 dateutil: 2.5.3 pytz: 2016.6.1 blosc: None bottleneck: None tables: 3.2.2 numexpr: 2.6.1 matplotlib: 1.5.3 openpyxl: None xlrd: 1.0.0 xlwt: 1.1.2 xlsxwriter: 0.9.2 lxml: None bs4: 4.5.1 html5lib: None httplib2: None apiclient: None sqlalchemy: 1.0.13 pymysql: None psycopg2: None jinja2: 2.8 boto: 2.42.0 pandas_datareader: None

[chris-b1]

Yeah, uint64 support is generally spotty. PR to fix welcome!

xref #14721, xref #4471