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## Everyone Can Learn Python Scholarship

### 1️⃣ Python 🐍 - CO2 Emissions

Now let's now move on to the competition and challenge.

### 📖 Background

You volunteer for a public policy advocacy organization in Canada, and your colleague asked you to help her draft recommendations for guidelines on CO2 emissions rules.

After researching emissions data for a wide range of Canadian vehicles, she would like you to investigate which vehicles produce lower emissions.

### 💾 The data I

#### The data is based on seven years of CO2 emissions data for Canadian vehicles (source):

- "Make" - The company that manufactures the vehicle.
- "Model" - The vehicle's model.
- "Vehicle Class" - Vehicle class by utility, capacity, and weight.
- "Engine Size(L)" - The engine's displacement in liters.
- "Cylinders" - The number of cylinders.
- "Transmission" - The transmission type: A = Automatic, AM = Automatic Manual, AS = Automatic with select shift, AV = Continuously variable, M = Manual, 3 - 10 = the number of gears.
- "Fuel Type" - The fuel type: X = Regular gasoline, Z = Premium gasoline, D = Diesel, E = Ethanol (E85), N = natural gas.
- "Fuel Consumption Comb (L/100 km)" - Combined city/highway (55%/45%) fuel consumption in liters per 100 km (L/100 km).
- "CO2 Emissions(g/km)" - The tailpipe carbon dioxide emissions in grams per kilometer for combined city and highway driving.

The data comes from the Government of Canada's open data website.

```
# Import the pandas and numpy packages
import pandas as pd
import numpy as np
# Load the data
cars = pd.read_csv('data/co2_emissions_canada.csv')
# create numpy arrays
cars_makes = cars['Make'].to_numpy()
cars_models = cars['Model'].to_numpy()
cars_classes = cars['Vehicle Class'].to_numpy()
cars_engine_sizes = cars['Engine Size(L)'].to_numpy()
cars_cylinders = cars['Cylinders'].to_numpy()
cars_transmissions = cars['Transmission'].to_numpy()
cars_fuel_types = cars['Fuel Type'].to_numpy()
cars_fuel_consumption = cars['Fuel Consumption Comb (L/100 km)'].to_numpy()
cars_co2_emissions = cars['CO2 Emissions(g/km)'].to_numpy()
def replace_fuel_type(cars):
#The fuel type: X = Regular gasoline, Z = Premium gasoline, D = Diesel, E = Ethanol (E85), N = natural gas.
return cars["Fuel Type"].replace('X', 'Regular gasoline').replace('Z', 'Premium gasoline').replace('D', 'Diesel').replace('E', 'Ethanol').replace('N', 'Natural gas')
# Preview the dataframe
cars
```

```
# Look at the first ten items in the CO2 emissions array
cars_co2_emissions[:10]
```

### 💪 Challenge I

Help your colleague gain insights on the type of vehicles that have lower CO2 emissions. Include:

- What is the median engine size in liters?
- What is the average fuel consumption for regular gasoline (Fuel Type = X), premium gasoline (Z), ethanol (E), and diesel (D)?
- What is the correlation between fuel consumption and CO2 emissions?
- Which vehicle class has lower average CO2 emissions, 'SUV - SMALL' or 'MID-SIZE'?
- What are the average CO2 emissions for all vehicles? For vehicles with an engine size of 2.0 liters or smaller?
- Any other insights you found during your analysis?

`cars_sort_by_emission = cars.sort_values(by='CO2 Emissions(g/km)', ascending = True)`

#### 1. What is the median engine size in liters?

```
import numpy
print(str(numpy.median(cars_engine_sizes)) + "L.")
```

#### 2. What is the average fuel consumption for regular gasoline (Fuel Type = X), premium gasoline (Z), ethanol (E), and diesel (D)?

```
cars_by_fuel_type = cars[cars["Fuel Type"]!="N"].groupby(by="Fuel Type")["Fuel Consumption Comb (L/100 km)"].mean()
pd.DataFrame(cars_by_fuel_type).sort_values(by="Fuel Consumption Comb (L/100 km)", ascending=True)
```

#### 3. What is the correlation between fuel consumption and CO2 emissions?

`print("The correlation between fuel consumption and emissions is " + str(np.round(cars["Fuel Consumption Comb (L/100 km)"].corr(cars["CO2 Emissions(g/km)"]), 2)))`

As we could expect, based on current fuel types, there is a direct impact in the CO2 emissions related to fuel consumption. The more fuel consumed, the more CO2 emissions.

#### 4. Which vehicle class has lower average CO2 emissions, 'SUV - SMALL' or 'MID-SIZE'?