你的错误在于这一句：

b = CustomBusinessDay(holidays)
 CustomBusinessDay这个类里面的holidays参数是一个关键字参数，不是一个位置参数，所以你进行实例化类的时候应该这样写

b = CustomBusinessDay(holidays=holidays)

这个类的部分帮助文件如下

help(CustomBusinessDay)

Help on class CustomBusinessDay in module pandas.tseries.offsets:

class CustomBusinessDay(_CustomMixin, BusinessDay)

| CustomBusinessDay(n=1, normalize=False, weekmask='Mon Tue Wed Thu Fri', holidays=None, calendar=None, offset=datetime.timedelta(0))

|

| DateOffset subclass representing possibly n custom business days,

| excluding holidays.

我上传个数据，

数据.xlsx

帮我看一下，谢谢!

int() argument must be a string, a bytes-like object or a number, not 'list'

During handling of the above exception, another exception occurred:

TypeError: `n` argument must be an integer, got <class 'list'>

TypeError                                 Traceback (most recent call last)pandas\_libs\tslibs\offsets.pyx in pandas._libs.tslibs.offsets.BaseOffset._validate_n()TypeError: int() argument must be a string, a bytes-like object or a number, not 'list'

During handling of the above exception, another exception occurred:TypeError                                 Traceback (most recent call last)<ipython-input-100-eab4994fcd77> in <module>     22         count_businessday(start_day,end_day)     23 ---> 24 sheet['工作日'] = sheet.apply(lambda x:count_businessday(x['出院时间'],x['归档日期']),axis=1)D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\frame.py in apply(self, func, axis, raw, result_type, args, **kwds)   7546             kwds=kwds,   7547         )-> 7548         return op.get_result()   7549    7550     def applymap(self, func) -> "DataFrame":D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\apply.py in get_result(self)    178             return self.apply_raw()    179 --> 180         return self.apply_standard()    181     182     def apply_empty_result(self):D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\apply.py in apply_standard(self)    269     270     def apply_standard(self):--> 271         results, res_index = self.apply_series_generator()    272     273         # wrap resultsD:\ProgramData\Anaconda3\lib\site-packages\pandas\core\apply.py in apply_series_generator(self)    298                 for i, v in enumerate(series_gen):    299                     # ignore SettingWithCopy here in case the user mutates--> 300                     results[i] = self.f(v)    301                     if isinstance(results[i], ABCSeries):    302                         # If we have a view on v, we need to make a copy because<ipython-input-100-eab4994fcd77> in <lambda>(x)     22         count_businessday(start_day,end_day)     23 ---> 24 sheet['工作日'] = sheet.apply(lambda x:count_businessday(x['出院时间'],x['归档日期']),axis=1)<ipython-input-100-eab4994fcd77> in count_businessday(start_day, end_day)      4                                     '2020-10-05','2020-10-06','2020-10-07','2020-10-08']      5     holidays=[pd.Timestamp(i) for i in holidays]----> 6     b = CustomBusinessDay(holidays)      7     bus_day = pd.date_range(start=start_day, end=end_day, freq=b)      8     length = len(bus_day)pandas\_libs\tslibs\offsets.pyx in pandas._libs.tslibs.offsets.CustomBusinessDay.__init__()pandas\_libs\tslibs\offsets.pyx in pandas._libs.tslibs.offsets.BusinessMixin.__init__()pandas\_libs\tslibs\offsets.pyx in pandas._libs.tslibs.offsets.BaseOffset.__init__()pandas\_libs\tslibs\offsets.pyx in pandas._libs.tslibs.offsets.BaseOffset._validate_n()TypeError: `n` argument must be an integer, got <class 'list'>

from pandas.tseries.offsets import CustomBusinessDay
def count_businessday(start_day,end_day):
    holidays=['2020-04-06','2020-05-01','2020-05-04','2020-05-05','2020-06-25','2020-10-01',
                                    '2020-10-05','2020-10-06','2020-10-07','2020-10-08']
    holidays=[pd.Timestamp(i) for i in holidays]
    b = CustomBusinessDay(holidays)
    bus_day = pd.date_range(start=start_day, end=end_day, freq=b)
    length = len(bus_day)
 
    extra_work_day = ['2020-04-26','2020-05-09','2020-06-28','2020-09-27','2020-10-10']
    extra_work_day = [pd.Timestamp(i) for i in extra_work_day]
    
    extra_len = 0
     
    for i in extra_work_day:
        if  i  >= start_day and i <= end_day:
            extra_len = extra_len+1
 
    return(length+extra_len-1)
 
    if __name__=='__main__':
        count_businessday(start_day,end_day)
        
sheet['工作日'] = sheet.apply(lambda x:count_businessday(x['出院时间'],x['归档日期']),axis=1)

问题在于你的extra_work_day= ['2020-04-26','2020-05-09','2020-06-28','2020-09-27','2020-10-10']
这个列表里面的元素是字符串，所以不能和时间戳对象进行比较，你需要变一下，把他变成时间戳对象，可以通过下面的方式：
extra_work_day= ['2020-04-26','2020-05-09','2020-06-28','2020-09-27','2020-10-10']

extra_work_day=[pd.Timestamp(i) for i in extra_work_day]

然后你就可以用原来的命令比较啦

from pandas.tseries.offsets import CustomBusinessDay
def count_businessday(start_day,end_day):
    b = CustomBusinessDay(holidays=['2020-04-06','2020-05-01','2020-05-04','2020-05-05','2020-06-25','2020-10-01',
                                    '2020-10-05','2020-10-06','2020-10-07','2020-10-08'])
    bus_day = pd.date_range(start=start_day, end=end_day, freq=b)
    length = len(bus_day)
 
    extra_work_day = ['2020-04-26','2020-05-09','2020-06-28','2020-09-27','2020-10-10']
    extra_len = 0
    dayday = Interval(start_day,end_day)
    for i in extra_work_day:
        if  i  in dayday: 
            extra_len = extra_len+1
 
    return(length+extra_len-1)
 
    if __name__=='__main__':
        count_businessday(start_day,end_day)

sheet['工作日'] = sheet.apply(lambda x:count_businessday(x['出院时间'],x['归档日期']),axis=1)

出现这个错误：

'<' not supported between instances of 'str' and 'Timestamp'

from pandas.tseries.offsets import CustomBusinessDay

def count_businessday(start_day,end_day):

b = CustomBusinessDay(holidays=['2020-04-06','2020-05-01','2020-05-04','2020-05-05','2020-06-25','2020-10-01',

'2020-10-05','2020-10-06','2020-10-07','2020-10-08'])

bus_day = pd.date_range(start=start_day, end=end_day, freq=b)

length = len(bus_day)

extra_work_day = ['2020-04-26','2020-05-09','2020-06-28','2020-09-27','2020-10-10']

extra_len = 0

dayday = Interval(start_day,end_day)

for i in extra_work_day:

if i in dayday:

extra_len = extra_len+1

return(length+extra_len-1)

if __name__=='__main__':

count_businessday(start_day,end_day)

sheet['工作日'] = sheet.apply(lambda x:count_businessday(x['出院时间'],x['归档日期']),axis=1)

sheet.head()

出现这个错误：

'<' not supported between instances of 'str' and 'Timestamp'

你好：比较运算用于数值之间的比较，如果你想比较两个Timestamp对象的话可以这样比较

import pandas as pd

a1=pd.Timestamp('2017-01-01T12')

b1=pd.Timestamp('2017-01-01T09')

c1=pd.Timestamp('2017-01-02T12')

print(a1>b1)

print(a1>c1)

好像这个性质还是等同于大于小于号，我是用之前的<= 表达式，出现'<' not supported between instances of 'str' and 'Timestamp'