Pandas sum column with scalar results in zeros

[jpiabrantes]

I am summing a column of a pandas dataframe with a scalar and the result is a column full of zeros. The weird thing is that sometimes it will return zeros and sometimes it won't.

With this code I get a similar error:

import pandas as pd
import numpy as np
from pdb import set_trace as pdb

for _ in xrange(100):
    data = np.random.randint(1,100000,1000000)
    df = pd.DataFrame(data,columns=['column'])
    scalar = np.random.randint(1,100000)
    df.column += scalar
    if df.column.max()==0:
        pdb()

My df.column gets full of zeros every now and then.

Discussion on stackoverflow:
http://stackoverflow.com/questions/35057969/pandas-sum-column-with-scalar-results-in-zeros

[jreback]

post pd.show_versions()

this is almost certainly #12023

you are on windows with numexpr=2.4.4

upgrade to numexpr=2.4.6 and all will be well

[jpiabrantes]

Here are my versions

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.11.final.0
python-bits: 64
OS: Windows
OS-release: 10
machine: AMD64
processor: Intel64 Family 6 Model 94 Stepping 3, GenuineIntel
byteorder: little
LC_ALL: None
LANG: en_GB

pandas: 0.17.1
nose: 1.3.7
pip: 8.0.1
setuptools: None
Cython: 0.23.4
numpy: 1.10.1
scipy: 0.16.0
statsmodels: None
IPython: 4.0.1
sphinx: 1.3.1
patsy: 0.4.0
dateutil: 2.4.2
pytz: 2015.7
blosc: None
bottleneck: 1.0.0
tables: 3.2.2
numexpr: 2.4.4
matplotlib: 1.5.0
openpyxl: 2.2.6
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: 0.7.7
lxml: 3.4.4
bs4: 4.4.1
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.0.9
pymysql: None
psycopg2: None
Jinja2: None

I updated to numexpr=2.4.6 and problem got fixed! Thank you very much!