Car to Buy
Lesson 19 of 19 in Coddy's Pandas Analytics course.
When using .sort_values it returns a dataframe where column_name is converted to index:
res = df.sort_values(by='column_name', ascending=True)An index is like an address; that's how any data point across the dataframe or series can be accessed.
When a column is converted to an index, it is no longer possible to access it the way we learned:
res["column_name"]This is not possible.
To convert the index back to a normal column, write: .reset_index:
res = df.sort_values(by='column_name', ascending=True).reset_index()Or make it two-stage steps:
res = df.sort_values(by='column_name', ascending=True)
res = res.reset_index()
Challenge
MediumThe CSV files car_raw_stats.csv and car_features.csv contain information about cars for sale.
Here is the first 5 lines of car_raw_stats.csv:
car_id,brand,price,popularity,year
1,ram,12584.93337,0.962070375,2008
2,mazda,15123.47674,0.356163012,2012
3,kia,15861.89672,0.110720597,2006
4,renault,12631.39906,0.153823182,2016Here is the first 5 lines of car_features.csv:
car_id,sits,has_phone_charger,is_comfortable
1,4,,1
2,4,,1
3,4,1,1
4,2,1,We need to find potential cars to buy.
- Any missing value is considered a
0. - Find the mean of each brand and investigate only the top
7brands. Filter all cars from these brands. - We are looking for a budget car - price smaller than
20000but the year should be bigger than 2005. - The car should have
4sits, we don't need a charger, but it needs to be comfortable. - Sort the cars in ascending order by the car id.
Save the result to df
Try it yourself
# pandas as pd is already imported
df_feat = pd.read_csv("./car_features.csv")
df_stat = pd.read_csv("./car_raw_stats.csv")
# Write your code below
All lessons in Pandas Analytics
4Data Analysis with Pandas
Descriptive StatisticsGrouping and Aggregating DataDifferent AggregationsMerge & Concat2Working with the DataFrame
Understanding DataFramesAccessing DataData Cleaning - Missing dataData Cleaning - More tools3Data Manipulation with Pandas
Return Requested ResultFilter DataAdd & DeleteModify DataModify StringsCustom Modifications