按年份Pandas的问题分组

import pandas as pd

# 创建一个示例DataFrame
data = {
    'date': ['2020-01-01', '2020-02-15', '2021-03-20', '2021-04-10'],
    'value': [100, 150, 200, 250]
}
df = pd.DataFrame(data)

# 将日期列转换为datetime类型
df['date'] = pd.to_datetime(df['date'])

# 按年份分组并计算每年的总和
grouped = df.groupby(df['date'].dt.year)['value'].sum()

print(grouped)

df['date'] = pd.to_datetime(df['date'], errors='coerce')

grouped = df.groupby(df['date'].dt.year)['value'].sum().fillna(0)

# 按季度分组
grouped_quarterly = df.groupby(df['date'].dt.to_period('Q'))['value'].sum()

# 按月份分组
grouped_monthly = df.groupby(df['date'].dt.month)['value'].sum()