自动加月份

import pandas as pd
from datetime import date,timedelta

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def add_month(d, md):#md为月份准备加入多少
    yd = md // 12# 超过12个月，加一年
    m = d.month + md % 12# 如果加入的月份大于12，除一下还是这个月份+余数即可
    if m != 12:# 如果加入的月份不等于12
        yd += m // 12
        m = m % 12
    return date(d.year + yd, m, d.day)
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# skiprows=5 标题栏从第6行开始。usecols="c:f" 左侧A,B列不要读，从C列读到F列  dtype={'ID':str} 把ID列定义为str
books=pd.read_excel("out.xlsx",skiprows=5,usecols="c:f",dtype={'ID':str,'性别':str,'日期':str})
# print(books)
start=date(2019,1,1)
for i in books.index:
    books['ID'].at[i]=i+1
    books['性别'].at[i]='Yes'if i%2==0 else "No"
    # books['日期'].at[i]=start+timedelta(days=i) # 这段是加日
    # books['日期'].at[i] = date(start.year+i,start.month,start.day) # 这段是加年
    books['日期'].at[i] = add_month(start,i) # 这段是加月份，有点难度的# # # # # # # # # # # # # # # # # # # # # # # # # # # 
print(books)

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