can nod concatenate character 'm' and a series

[goldenbull]

Code Sample, a copy-pastable example if possible

import pandas as pd

df = pd.DataFrame({"a": [1, 2, 3], })
print("m" + df["a"].astype(str))

Problem description

Traceback (most recent call last):
  File "D:/test/plot1.py", line 4, in <module>
    print("m" + df["a"].astype(str))
  File "C:\Python37\lib\site-packages\pandas\core\ops\__init__.py", line 1016, in wrapper
    assert np.isnat(right)
TypeError: ufunc 'isnat' is only defined for datetime and timedelta.

Expected Output

m1
m2
m3

Output of pd.show_versions()

INSTALLED VERSIONS ------------------ commit : None python : 3.7.4.final.0 python-bits : 64 OS : Windows OS-release : 10 machine : AMD64 processor : Intel64 Family 6 Model 142 Stepping 10, GenuineIntel byteorder : little LC_ALL : None LANG : None LOCALE : None.None

pandas : 0.25.3
numpy : 1.17.2
pytz : 2019.2
dateutil : 2.8.0
pip : 19.3.1
setuptools : 41.0.1
Cython : None
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.10.1
IPython : 7.8.0
pandas_datareader: None
bs4 : None
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : 3.1.1
numexpr : None
odfpy : None
openpyxl : 2.6.3
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : 1.3.1
sqlalchemy : None
tables : None
xarray : None
xlrd : 1.2.0
xlwt : None
xlsxwriter : None

[hwalinga]

This seems to be fixed in the master.

[jschendel]

Yes, this is a dupe of #28658, which has been fixed on master and will be part of the 1.0 release.

In [1]: import pandas as pd; pd.__version__
Out[1]: '0.26.0.dev0+918.gcd013b41b'

In [2]: df = pd.DataFrame({"a": [1, 2, 3]})

In [3]: "m" + df["a"].astype(str)
Out[3]: 
0    m1
1    m2
2    m3
Name: a, dtype: object