title: Troubleshooting" ValueError: Index Date Invalid"?
body: <p>I'm learning Python 3.7.4 using IDLE. I am receiving an error saying index date invalid.</p>
  
  <p>I've had success using excel files that i've formatted with dates &amp; data in individual col's (A-C) but this is a csv file with all the data in one col separated by commas. In the format with the data formatted i would use the below...</p>
  
  <pre><code>ANTM = pd.read_csv(r'C:\..\ANTM_stock'.csv', parse_dates= True, index_col=0)
  </code></pre>
  
  <p>I'm pretty sure the parse_dates=True, index_col=0 is indicating look at the first col &amp; interpret them as dates. This works fine.</p>
  
  <pre><code>#Markowitz efficient frontier
  
  import numpy as np
  import pandas as pd
  import matplotlib.pyplot as plt
  import pandas_datareader.data as web
  
  companies = ['WMT','FB']
  df = pd.read_csv(r'C:\...\Walmart_FB_2014_2017.csv', index_col='Date')
  
  df.head()
  </code></pre>
  
  <p>I expected to see a table with some data instead i received the error below.</p>
  
  <pre><code>ValueError: Index Date invalid
  </code></pre>
  
  <p>Below is a sample of the data (It is all in Col A)</p>
  
  <p><a href="https://i.stack.imgur.com/KkdA7.png" rel="nofollow noreferrer">Data in CSV File</a></p>