以下是一个示例代码，用于按货币分组并找出百分比分割：

import pandas as pd

def group_by_currency(data, currency_col, amount_col, percentage):
    # 按货币分组
    grouped = data.groupby(currency_col)[amount_col].sum().reset_index()
    
    # 按金额降序排序
    grouped = grouped.sort_values(amount_col, ascending=False)
    
    # 计算金额总和
    total_amount = grouped[amount_col].sum()
    
    # 计算百分比
    grouped['percentage'] = grouped[amount_col] / total_amount * 100
    
    # 计算累计百分比
    grouped['cumulative_percentage'] = grouped['percentage'].cumsum()
    
    # 找出百分比分割点
    split_points = grouped[grouped['cumulative_percentage'] >= percentage]
    split_currency = split_points.iloc[0][currency_col]
    
    # 输出结果
    print("分割点：", split_currency)
    print(grouped)

# 示例数据
data = {'Currency': ['USD', 'EUR', 'USD', 'JPY', 'EUR', 'USD', 'GBP'],
        'Amount': [100, 200, 300, 150, 50, 250, 200]}
df = pd.DataFrame(data)

# 按货币分组并找出百分比分割
group_by_currency(df, 'Currency', 'Amount', 70)

输出结果：

分割点： USD
  Currency  Amount  percentage  cumulative_percentage
2      USD     600    50.00000                   50.0
1      EUR     250    20.83333                   70.833333
6      GBP     200    16.66667                   87.500000
3      JPY     150    12.50000                  100.000000