# Profile: Data · NumPy and pandas
import numpy as np
minutes = np.array([[20, 30, 10], [40, 20, 30]], dtype=float)
print("Shape:", minutes.shape)
print("Each day's total:", minutes.sum(axis=1).tolist())
print("Each topic's total:", minutes.sum(axis=0).tolist())
print("Hours:", (minutes / 60).round(2).tolist())
print("At least 30 minutes:", minutes[minutes >= 30].tolist())
# Basic slicing can share memory. Copy before making independent edits.
first_day_copy = minutes[0].copy()
first_day_copy[0] = 99
print("Original first value:", minutes[0, 0])
