여러 열을 기반으로 Pandas DataFrame에서 동일한 행의 빈도를 어떻게 계산할 수 있나요?

   Group | Size |
---------+------+
   Short | Small |
   Short | Small |
   Moderate | Medium |
   Moderate | Small |
   Tall | Large |

<code class="python">import pandas as pd

# Load the sample data
data = {'Group': ['Short', 'Short', 'Moderate', 'Moderate', 'Tall'], 'Size': ['Small', 'Small', 'Medium', 'Small', 'Large']}
df = pd.DataFrame(data)

# Option 1:
dfg = df.groupby(by=["Group", "Size"]).size()

# Option 2: Reset the index to convert the Series to a DataFrame
dfg = df.groupby(by=["Group", "Size"]).size().reset_index(name="Time")

# Option 3: Use as_index=False to create a DataFrame without an index
dfg = df.groupby(by=["Group", "Size"], as_index=False).size()</code>

  Group | Size | Time
--------+------+------
  Moderate | Medium | 1
  Moderate | Small | 1
  Short | Small | 2
  Tall | Large | 1