import pandas as pd
import pyarrow as pa
import pyarrow.csv as csv
import time

NUM_ROWS = 10000000
NUM_COLS = 20

# Example Multi-Index DataFrame
df = pd.DataFrame(
    {
        f"col_{col_idx}": range(col_idx * NUM_ROWS, (col_idx + 1) * NUM_ROWS)
        for col_idx in range(NUM_COLS)
    }
)
df = df.set_index(["col_0", "col_1"], drop=False)

# Timing Operation A
start_time = time.time()
df.to_csv("file_A.csv", index=False)
end_time = time.time()
print(f"Operation A time: {end_time - start_time} seconds")

# Timing Operation B
start_time = time.time()
df_reset = df.reset_index(drop=True)
df_reset.to_csv("file_B.csv", index=False)
end_time = time.time()
print(f"Operation B time: {end_time - start_time} seconds")