df = pd.DataFrame({'float': [1.0],
'int': [1],
'datetime': [pd.Timestamp('20180310')],
'string': ['foo']})
df.dtypes
float float64
int int64
datetime datetime64[ns]
string object
dtype: object
d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df.dtypes
col1 int64
col2 int64
dtype: object