CODEWITHSUNDEEP
pandas
Saurav Ale
Saurav Ale

Reputation: 3

how to compare the values of two columns using condition, and assign a value when that condition is met

I want to compare the home_score and away_score column values and if homescore<awayscore assigning homeloss , if homescore>awayscore assigning homewin and if homescore = awayscore assingning draw in new columns

era1800_1900 = era(eras,1800,1900)
era1800_1900["result"] = era1800_1900[(era1800_1900["home_score"] < era1800_1900["away_score"] == "Lose")]

I expect another column result in my data frame with values homeloss, homewin and draw based on the condition scores but i get this error when i used the following code

--era1800_1900 = era(eras,1800,1900)
era1800_1900["result"] = era1800_1900[(era1800_1900["home_score"] < era1800_1900["away_score"] == "Lose")]------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-78-58ef8c4a0715> in <module>
      1 era1800_1900 = era(eras,1800,1900)
----> 2 era1800_1900["result"] = era1800_1900[(era1800_1900["home_score"] < era1800_1900["away_score"] == "Lose")]

~\Anaconda3 new\lib\site-packages\pandas\core\generic.py in __nonzero__(self)
   1574         raise ValueError("The truth value of a {0} is ambiguous. "
   1575                          "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
-> 1576                          .format(self.__class__.__name__))
   1577 
   1578     __bool__ = __nonzero__

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

Upvotes: 0

Views: 30

Answers (1)

Parth Batra
Parth Batra

Reputation: 87

Try the following approach:

era['result'] = None
era.loc[era[era['A'] < era['B']].index.values,'result'] = 'homelose'
era.loc[era[era['A'] > era['B']].index.values,'result'] = 'homewin'
era.loc[era[era['A'] < era['B']].index.values,'result'] = 'homedraw'

If you are comfortable with functions, look at this example

Upvotes: 1

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