Course Notes: Exploratory Data Analysis in Python

# Count the number of missing values in each column
print(planes.isna().sum())

# Find the five percent threshold
threshold = len(planes) * 0.05

# Create a filter
cols_to_drop = planes.columns[planes.isna().sum() <= threshold]

# Drop missing values for columns below the threshold
planes.dropna(subset=cols_to_drop, inplace=True)

print(planes.isna().sum())

# Calculate median plane ticket prices by Airline
airline_prices = planes.groupby("Airline")["Price"].median()

print(airline_prices)

# Convert to a dictionary
prices_dict = airline_prices.to_dict()

# Map the dictionary to missing values of Price by Airline
planes["Price"] = planes["Price"].fillna(planes["Airline"].map(prices_dict))

# Check for missing values
print(planes.isna().sum())

# Filter the DataFrame for object columns
non_numeric = planes.select_dtypes("object")

# Loop through columns
for c in non_numeric.columns:
  
  # Print the number of unique values
  print(f"Number of unique values in {c} column: ", non_numeric[c].nunique())

# Filter the DataFrame for object columns
non_numeric = planes.select_dtypes("object")

# Loop through columns
for c in non_numeric.columns:
  # Print the number of unique values
  print(f"Number of unique values in {c} column: ", non_numeric[c].nunique())

# Create a list of categories
flight_categories = ["Short-haul", "Medium", "Long-haul"]

# Create short-haul values
short_flights = "0h|1h|2h|3h|4h"

# Create medium-haul values
medium_flights = "5h|6h|7h|8h|9h"

# Create long-haul values
long_flights = "10h|11h|12h|13h|14h|15h|16h"

# Create conditions for values in flight_categories to be created
conditions = [
    (planes["Duration"].str.contains(short_flights)),
    (planes["Duration"].str.contains(medium_flights)),
    (planes["Duration"].str.contains(long_flights))
]

# Apply the conditions list to the flight_categories
planes["Duration_Category"] = np.select(conditions, 
                                        flight_categories,
                                        default="Extreme duration")

# Plot the counts of each category
sns.countplot(data=planes, x="Duration_Category")
plt.show()