Credit rating

Nowadays, there are three major credit ratings agents in the USA: Moody's, Standard, and Poor's and Fitch. Their websites are http://www.moodys.com/, http://www.standardandpoors.com/en_US/web/guest/home, and https://www.fitchratings.com/site/home. Although their ratings have different notations (letters), it is easy to translate one letter rating from a rating agency to another one. Based on the following link at http://www.quadcapital.com/Rating%20Agency%20Credit%20Ratings.pdf, a dataset called creditRatigs3.pkl is generated, which can be downloaded at the author's website, http://canisius.edu/~yany/python/creditRatings3.pkl. Assume that it is located under C:/temp/.

The following codes show its contents:

import pandas as pd
x=pd.read_pickle("c:/temp/creditRatings3.pkl")
print(x)
       Moody's S&P Fitch  NAIC  InvestmentGrade
0      Aaa   AAA   AAA     1                1
1      Aa1   AA+   AA+     1                1
2      Aa2    AA    AA...