[] (__getitem__) boolean indexing assignment bug with nans #9731
Description
See repro below:
import pandas as pd import numpy as np temp = pd.Series(np.random.randn(10)) temp[3:6] = np.nan temp[8] = np.nan nan_index = np.isnan(temp) # this works temp1 = temp.copy() temp1[nan_index] = [99, 99, 99, 99] temp1[nan_index] 3 99 4 99 5 99 8 99 dtype: float64 # this doesn't - values look like they're being assigned in a different order? temp2 = temp.copy() temp2[nan_index] = [99, 99, 99, np.nan] 3 NaN 4 99 5 99 8 99 dtype: float64 # ... but it works properly when using .loc temp2 = temp.copy() temp2.loc[nan_index] = [99, 99, 99, np.nan] 3 99 4 99 5 99 8 NaN dtype: float64output of show_versions():
INSTALLED VERSIONS ------------------ commit: None python: 2.7.9.final.0 python-bits: 64 OS: Windows OS-release: 7 machine: AMD64 processor: Intel64 Family 6 Model 60 Stepping 3, GenuineIntel byteorder: little LC_ALL: None LANG: None pandas: 0.16.0 nose: 1.3.4 Cython: 0.21.2 numpy: 1.9.2 scipy: 0.14.0 statsmodels: 0.5.0 IPython: 3.0.0 sphinx: 1.2.3 patsy: 0.2.1 dateutil: 2.4.1 pytz: 2015.2 bottleneck: 0.8.0 tables: 3.1.1 numexpr: 2.3.1 matplotlib: 1.4.0 openpyxl: 2.0.2 xlrd: 0.9.3 xlwt: 0.7.5 xlsxwriter: 0.6.6 lxml: 3.4.2 bs4: 4.3.2 html5lib: 0.999 httplib2: 0.8 apiclient: None sqlalchemy: 0.9.8 pymysql: None psycopg2: None