在Python中相当于R的group_by，filter，duplicate？

import pandas as pd

# 创建一个DataFrame
data = {'A': ['foo', 'bar', 'foo', 'bar', 'foo', 'bar', 'foo', 'foo'],
        'B': ['one', 'one', 'two', 'two', 'two', 'one', 'two', 'one'],
        'C': [1, 2, 3, 4, 5, 6, 7, 8]}
df = pd.DataFrame(data)

# 对列A进行分组，并计算每个组的平均值
grouped = df.groupby('A')
result = grouped.mean()

print(result)

import pandas as pd

# 创建一个DataFrame
data = {'A': ['foo', 'bar', 'foo', 'bar', 'foo', 'bar', 'foo', 'foo'],
        'B': ['one', 'one', 'two', 'two', 'two', 'one', 'two', 'one'],
        'C': [1, 2, 3, 4, 5, 6, 7, 8]}
df = pd.DataFrame(data)

# 筛选出列A为'foo'的数据行
filtered = df[df['A'] == 'foo']

print(filtered)

import pandas as pd

# 创建一个DataFrame
data = {'A': ['foo', 'bar', 'foo', 'bar', 'foo', 'bar', 'foo', 'foo'],
        'B': ['one', 'one', 'two', 'two', 'two', 'one', 'two', 'one'],
        'C': [1, 2, 3, 4, 5, 6, 7, 8]}
df = pd.DataFrame(data)

# 判断是否存在重复行
is_duplicate = df.duplicated()

# 删除重复行
df_no_duplicate = df.drop_duplicates()

print(is_duplicate)
print(df_no_duplicate)