Missing FIle for Indexing
#### Code Sample, a copy-pastable example if possible
##Imports
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt 

def read_data():
    file_name = 'temperature_2017.csv'
    data = pd.read_csv(file_name)
    df = pd.DataFrame(data,columns=['timestamp', 'temperature'])
    #print(df) #display data
    return df

data = read_data()

def plot_data(df):
    fig, axes = plt.subplots()
    x_data = df.loc['timestamp']
    y_data = df.loc['temperature']
    plt.plot(x_data,y_data,'--r')
    plt.show()

plot_data(data)

Issue Description: I get an error whenever I try to index a dataframe using df.loc[] - stating that "index_class_helper.pxi' file does not exist. Here is the error: 

Traceback (most recent call last):
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\indexes\base.py", line 2657, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 108, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 129, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index_class_helper.pxi", line 91, in pandas._libs.index.Int64Engine._check_type
KeyError: 'timestamp'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\Users\liamw\.vscode\extensions\ms-python.python-2019.5.18875\pythonFiles\ptvsd_launcher.py", line 43, in <module>
    main(ptvsdArgs)
  File "c:\Users\liamw\.vscode\extensions\ms-python.python-2019.5.18875\pythonFiles\lib\python\ptvsd\__main__.py", line 434, in main
    run()
  File "c:\Users\liamw\.vscode\extensions\ms-python.python-2019.5.18875\pythonFiles\lib\python\ptvsd\__main__.py", line 312, in run_file
    runpy.run_path(target, run_name='__main__')
  File "C:\Users\liamw\Python\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "C:\Users\liamw\Python\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Users\liamw\Python\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "c:\Users\liamw\OneDrive\McMasterUniversity\2019-2020 School Year\SpringSummerProjects\DataScience\bee_temp.py", line 28, in <module>
    plot_data(data)
  File "c:\Users\liamw\OneDrive\McMasterUniversity\2019-2020 School Year\SpringSummerProjects\DataScience\bee_temp.py", line 23, in plot_data
    x_data = df.loc['timestamp']
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\indexing.py", line 1500, in __getitem__
    return self._getitem_axis(maybe_callable, axis=axis)
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\indexing.py", line 1913, in _getitem_axis
    return self._get_label(key, axis=axis)
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\indexing.py", line 141, in _get_label
    return self.obj._xs(label, axis=axis)
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\generic.py", line 3585, in xs
    loc = self.index.get_loc(key)
  File "C:\Users\liamw\Python\lib\site-packages\pandas\core\indexes\base.py", line 2659, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas\_libs\index.pyx", line 108, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 129, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index_class_helper.pxi", line 91, in pandas._libs.index.Int64Engine._check_type
KeyError: 'timestamp'


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#### Expected Output
Should output a series based on my selection from the dataframe

#### Output of ``pd.show_versions()``

<details>

[paste the output of ``pd.show_versions()`` here below this line]

</details>
