import pandas as pd

# 读取 Excel
df = pd.read_excel('file.xlsx')  # 默认第一个 sheet
df = pd.read_excel('file.xlsx', sheet_name='Sheet2')
all_sheets = pd.read_excel('file.xlsx', sheet_name=None)  # 所有 sheet

# 基础分析
df.head()       # 预览
df.info()       # 列信息
df.describe()   # 统计摘要

from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill, Alignment

wb = Workbook()
sheet = wb.active

# 添加数据
sheet['A1'] = '标题'
sheet['B1'] = 100
sheet.append(['行', '数据', '示例'])

# 添加公式（重要：使用公式而非硬编码值）
sheet['B5'] = '=SUM(B2:B4)'
sheet['C5'] = '=AVERAGE(C2:C4)'

# 格式化
sheet['A1'].font = Font(bold=True, color='FF0000')
sheet['A1'].fill = PatternFill('solid', fgColor='FFFF00')
sheet['A1'].alignment = Alignment(horizontal='center')

# 列宽
sheet.column_dimensions['A'].width = 20

wb.save('output.xlsx')

from openpyxl import load_workbook

wb = load_workbook('existing.xlsx')
sheet = wb.active

# 修改单元格
sheet['A1'] = '新值'

# 插入/删除行列
sheet.insert_rows(2)
sheet.delete_cols(3)

# 新建sheet
new_sheet = wb.create_sheet('NewSheet')

wb.save('modified.xlsx')

# 正确：让Excel 计算
sheet['B10'] = '=SUM(B2:B9)'

# 错误：Python 计算后硬编码
total = sum(values)
sheet['B10'] = total  # 不要这样做

# DataFrame导出
df.to_excel('output.xlsx', index=False)

# 多sheet 导出
with pd.ExcelWriter('output.xlsx') as writer:
    df1.to_excel(writer, sheet_name='Sheet1')
    df2.to_excel(writer, sheet_name='Sheet2')