import pandas as pd
import math

# 1. Collect data in a standard Python list
data_list = []

for radius in range(1, 4):
    circumference = 2 * math.pi * radius
    area = math.pi * radius * radius

    # Store as a dictionary matching column names
    data_list.append({"Circumference": circumfrence, "Area": area})

# 2. Create the DataFrame all at once
df = pd.DataFrame(data_list)
print(df)