Key error not in index pandas

I have a dataframe called delivery and when I print(delivery.columns) I get the following:

Index(['Complemento_endereço', 'cnpj', 'Data_fundação', 'Número',
   'Razão_social', 'CEP', 'situacao_cadastral', 'situacao_especial', 'Rua',
   'Nome_Fantasia', 'last_revenue_normalized', 'last_revenue_year',
   'Telefone', 'email', 'Capital_Social', 'Cidade', 'Estado',
   'Razão_social', 'name_bairro', 'Natureza_Jurídica', 'CNAE', '#CNAE',
   'CNAEs_secundários', 'Pessoas', 'percent'],
  dtype='object')

Well, we can clearly see that there is a column ‘Rua’.

Also, if I print(delivery.Rua) I get a proper result:

82671                         R JUDITE MELO DOS SANTOS
817797                                R DOS GUAJAJARAS
180081           AV MARCOS PENTEADO DE ULHOA RODRIGUES
149373                                 AL MARIA TEREZA
455511                               AV RANGEL PESTANA
...

Even if I write «if ‘Rua’ in delivery.columns: print(‘here I am’)» it does print the ‘here I am’. So ‘Rua’ is in fact there.

Well, in the immediate line after I have this code:

delivery=delivery.set_index('cnpj')[['Razão_social','Nome_Fantasia','Data_fundação','CEP','Estado','Cidade','Bairro','Rua','Número','Complemento_endereço','Telefone','email','Capital_Social', 'CNAE', '#CNAE', 'Natureza_Jurídica','Pessoas' ]]

And voilá, I get this weird error:

Traceback (most recent call last):
File "/file.py", line 45, in <module>
   'Telefone', 'email', 'Capital_Social', 'Cidade', 'Estado',
   'Razão_social', 'name_bairro', 'Natureza_Jurídica', 'CNAE', '#CNAE',
'Telefone','email','Capital_Social', 'CNAE', '#CNAE', 'Natureza_Jurídica','Pessoas' ]]
   'CNAEs_secundários', 'Pessoas', 'percent'],
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/frame.py", line 1991, in __getitem__
  dtype='object')
return self._getitem_array(key)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/frame.py", line 2035, in _getitem_array
indexer = self.ix._convert_to_indexer(key, axis=1)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/indexing.py", line 1214, in _convert_to_indexer
raise KeyError('%s not in index' % objarr[mask])
KeyError: "['Rua'] not in index"

Can someone help? I tried stackoverflow but no one could help. I’m starting to think I’m crazy and ‘Rua’ is an illusion of my troubled mind.

ADDITIONAL INFO

I’m using this code right before the error line:

delivery=pd.DataFrame()

for i in selection.index:
    sample=groups.get_group(selection['#CNAE'].loc[i]).sample(selection['samples'].loc[i])
    delivery=pd.concat((delivery,sample)).sort_values('Capital_Social',ascending=False)


print(delivery.columns)
print(delivery.Rua)
print(delivery.set_index('cnpj').columns)

delivery=delivery.set_index('cnpj')[['Razão_social','Nome_Fantasia','Data_fundação','CEP','Estado','Cidade','Bairro','Rua','Número','Complemento_endereço',
                                 'Telefone','email','Capital_Social', 'CNAE', '#CNAE', 'Natureza_Jurídica','Pessoas' ]]

EDIT

New weird stuff:
I gave up and deleted ‘Rua’ from that last piece of code, wishing that it would work. For my surprise, I had the same problem but now with the column ‘Número’.

delivery=delivery.set_index('cnpj')[['Razão_social','Nome_Fantasia','Data_fundação','CEP','Estado','Cidade','Bairro','Número','Complemento_endereço',
                                                 'Telefone','email','Capital_Social', 'CNAE', '#CNAE', 'Natureza_Jurídica' ]]

KeyError: "['Número'] not in index"

EDIT 2

And then I gave up on ‘Número’ and took it out. Then the same problem happened with ‘Complemento_endereço’. Then I deleted ‘Complemento_endereço’. And it happend to ‘Telefone’ and so on.

** EDIT 3 **

If I do a pd.show_versions(), that’s the output:

INSTALLED VERSIONS

commit: None
python: 3.5.0.final.0
python-bits: 64
OS: Darwin
OS-release: 16.5.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: None

pandas: 0.18.1
nose: None
pip: 8.1.2
setuptools: 18.2
Cython: None
numpy: 1.11.0
scipy: 0.17.1
statsmodels: 0.6.1
xarray: None
IPython: None
sphinx: None
patsy: 0.4.1
dateutil: 2.5.3
pytz: 2016.4
blosc: None
bottleneck: None
tables: None
numexpr: None
matplotlib: 1.5.1
openpyxl: None
xlrd: 1.0.0
xlwt: None
xlsxwriter: None
lxml: None
bs4: 4.5.1
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.1.3
pymysql: 0.7.11.None
psycopg2: None
jinja2: None
boto: None
pandas_datareader: None
None

The KeyError in Pandas occurs when you try to access the columns in pandas DataFrame, which does not exist, or you misspell them. 

Typically, we import data from the excel name, which imports the column names, and there are high chances that you misspell the column names or include an unwanted space before or after the column name.

The column names are case-sensitive, and if you make a mistake, then Python will raise an exception KeyError: ‘column_name

Let us take a simple example to demonstrate KeyError in Pandas. In this example, we create a pandas DataFrame of employee’s data, and let’s say we need to print all the employee names.

# import pandas library
import pandas
import numpy as np

# create pandas DataFrame
df =  pandas.DataFrame(np.array([["Jack", 22, "US"], ["Chandler", 55, "Canada"], ["Ross", 48, "India"]]),
                   columns=['name', 'age', 'country'])

# print names of employee
print(df["Name"])

Output

    raise KeyError(key) from err
KeyError: 'Name'

When we run the program, Python raises KeyError, since we have misspelled the “name” column as “Name”.

Solution KeyError in Pandas

We can fix the issue by correcting the spelling of the key. If we are not sure what the column names are, we can print all the columns into the list as shown below.

# import pandas library
import pandas
import numpy as np

# create pandas DataFrame
df =  pandas.DataFrame(np.array([["Jack", 22, "US"], ["Chandler", 55, "Canada"], ["Ross", 48, "India"]]),
                   columns=['name', 'age', 'country'])

# print names of employee
print(df["name"])

Output

0        Jack
1    Chandler
2        Ross
Name: name, dtype: object

We can now see a column called “name,” and we can fix our code by providing the correct spelling as a key to the pandas DataFrame, as shown below.

We can also avoid the KeyErrors raised by the compilers when an invalid key is passed. The DataFrame has a get method where we can give a column name and retrieve all the column values.

Syntax : DataFrame.get( 'column_name' , default = default_value_if_column_is_not_present)

If there are any misspelled or invalid columns, the default value will be printed instead of raising a KeyError. Let’s look at an example to demonstrate how this works.

# import pandas library
import pandas
import numpy as np

# create pandas DataFrame
df = pandas.DataFrame(np.array([["Jack", 22, "US"], ["Chandler", 55, "Canada"], ["Ross", 48, "India"]]),
                      columns=['name', 'age', 'country'])

# print names of employee
print(df.get("Name", default="Name is not present"))

‘Output

Name is not present

And if we provide the correct column name to the DataFrame.get() method, it will list all the column values present in that.

# import pandas library
import pandas
import numpy as np

# create pandas DataFrame
df = pandas.DataFrame(np.array([["Jack", 22, "US"], ["Chandler", 55, "Canada"], ["Ross", 48, "India"]]),
                      columns=['name', 'age', 'country'])

# print names of employee
print(df.get("name", default="Name is not present"))

Output

0        Jack
1    Chandler
2        Ross
Name: name, dtype: object