BUG: ZERO WIDTH NO-BREAK SPACE in column name causes a reading failure

[omarbelaggoun]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• (optional) I have confirmed this bug exists on the master branch of pandas.

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Note: Please read this guide detailing how to provide the necessary information for us to reproduce your bug.

Code Sample, a copy-pastable example

test excel.xlsx

# Your code here
import pandas as pd
df=pd.read_excel('test excel.xlsx')
df

Problem description

I have a customer that is sending me a file that has ZERO WIDTH NO-BREAK SPACE
only the first header reads unless the character is deleted
I created a repro by copying the header from the original file to the new one in excel

Expected Output

Building Park Name	Building Name	New / Renewal	Address	City	State	Class 

Output of pd.show_versions()

INSTALLED VERSIONS

commit : None
python : 3.7.6.final.0
python-bits : 64
OS : Windows
OS-release : 10
machine : AMD64
processor : Intel64 Family 6 Model 158 Stepping 10, GenuineIntel
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.None

pandas : 0.25.3
numpy : 1.18.1
pytz : 2019.3
dateutil : 2.8.1
pip : 20.1.1
setuptools : 41.2.0
Cython : None
pytest : 5.3.5
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : 1.2.8
lxml.etree : None
html5lib : 1.0.1
pymysql : None
psycopg2 : None
jinja2 : 2.10.3
IPython : 7.11.1
pandas_datareader: None
bs4 : 4.8.2
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : 3.1.2
numexpr : None
odfpy : None
openpyxl : 3.0.3
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : 1.4.1
sqlalchemy : 1.3.12
tables : None
xarray : None
xlrd : 1.2.0
xlwt : None
xlsxwriter : 1.2.8

[MarcoGorelli]

Thanks @omarbelaggoun for the report, here's something copy-and-pasteable:

import pandas as pd                                                     

df = pd.read_excel('https://github.com/pandas-dev/pandas/files/5214984/test.excel.xlsx')
df

which returns

Empty DataFrame
Columns: [Building Park Name]
Index: []

[asishm]

problem arises from this section that gets called from self._infer_columns()

https://github.com/pandas-dev/pandas/blob/master/pandas/io/parsers.py#L2942-L2946

        # This was the first line of the file,
        # which could contain the BOM at the
        # beginning of it.
        if self.pos == 1:
            line = self._check_for_bom(line)

this changes line from ['\ufeffBuilding Park Name', 'Building Name', 'New / Renewal', 'Address', 'City', 'State', 'Class'] to ['Building Park Name']

[asishm]

a simpler example (without going the entire excel route)

In [1]: import pandas as pd
In [11]: from io import StringIO

In [20]: data = '''\ufeffHead1,Head2,Head3'''

In [21]: pd.read_csv(StringIO(data))
Out[21]: 
Empty DataFrame
Columns: [Head1, Head2, Head3]
Index: []

In [22]: pd.read_csv(StringIO(data), engine='python')
Out[22]: 
Empty DataFrame
Columns: [Head1]
Index: []

[MarcoGorelli]

Thanks @asishm !