import pandas as pd

df = pd.DataFrame({
    "name": ["Alice", "Bob", "Charlie", "David"],
    "age": [25, 30, 35, 40],
    "gender": ["F", "M", "M", "M"]
})

print(df)

# 输出：
#      name  age gender
# 0   Alice   25      F
# 1     Bob   30      M
# 2 Charlie   35      M
# 3   David   40      M

# 修改行索引值
df.index = ["a", "b", "c", "d"]
print(df)

# 输出：
#      name  age gender
# a   Alice   25      F
# b     Bob   30      M
# c Charlie   35      M
# d   David   40      M

# 修改列索引值
df.columns = ["姓名", "年龄", "性别"]
print(df)

# 输出：
#       姓名  年龄 性别
# a   Alice  25  F
# b     Bob  30  M
# c Charlie  35  M
# d   David  40  M

# 修改行索引值
df = df.rename({"a": "A", "b": "B", "c": "C", "d": "D"}, axis=0)
print(df)

# 输出：
#       姓名  年龄 性别
# A   Alice  25  F
# B     Bob  30  M
# C Charlie  35  M
# D   David  40  M

# 修改列索引值
df = df.rename({"姓名": "name", "年龄": "age", "性别": "gender"}, axis=1)
print(df)

# 输出：
#      name  age gender
# A   Alice   25      F
# B     Bob   30      M
# C Charlie   35      M
# D   David   40      M

# 将 name 列设置为行索引
df = df.set_index("name")
print(df)

# 输出：
#          age gender
# name               
# Alice     25      F
# Bob       30      M
# Charlie   35      M
# David     40      M

# 将 name 和 gender 列设置为多级行索引
df = df.set_index(["name", "gender"])
print(df)

# 输出：
#                age
# name    gender    
# Alice   F       25
# Bob     M       30
# Charlie M       35
# David   M       40

# 将行索引重置为默认的整数索引
df = df.reset_index()
print(df)

# 输出：
#      name  age gender
# 0   Alice   25      F
# 1     Bob   30      M
# 2 Charlie   35      M
# 3   David   40      M