pandas_questions.py

pandas_questions.py

import pandas as pd

"""
testdata.csv looks like this:
price1,price2,price3,type
20.00,40.00,60.00,20
40.00,10.00,30.00,10
3.00,15.00,47.42,20
"""


#1. How to add a column that would be show the result of the equivalent of Excel's: 
#=if(and(sum(b2:f2)<100,h2=20),"Y","N")
##  Note:  You'll want to create a function that performs this calculation
##         that's what Excel is doing.
def determine_yes_no_col(row):
    threshhold = 100
    if row['type'] == 20:
        # calculate sum of a range like sum(b2:f2)
        # verify that it's less than your threshhold of 100
        if sum(row['price1':'price3']) < threshhold:
            return 'Y'
    return 'N'

# Read in some data
testdata = pd.read_csv("testdata.csv")

# Add your calculated column
# Calls the determine_yes_no_col function for every Series in the pandas DataFrame
testdata['YesOrNo'] = testdata.apply(determine_yes_no_col, axis=1)


# 2. Subset the dataset say if the Column 'a'  = "Y" and  column  'b' ="N"
# Subset of the dataset where 'type' is 20 and 'YesOrNo' is 'N'
subset = testdata[(testdata['type']==20) & (testdata['YesOrNo'] == 'N')]


# 3. is covered in the determine_yes_no_col function