这是我在这里提出的第一个问题,所以如果我写了很多东西并且提前多多感谢你看看,我最诚挚的道歉。
我已经编写了一个函数,如果需要的话,应该调用自己x次,如果不成功则不返回任何内容。但是,当函数似乎成功时,它仍然返回None。
背景:我有许多目录代表2009年的月份。虽然不是所有的月份都存在,但是如果是这种情况,我想上个月,检查该月的目录是否存在如果没有继续在一个月后回到社区,为期6个月。
下面你看到date_tag中的月份09,在我的测试用例中不存在。 08或07都没有。因此函数应该返回06但是它返回None。
import pdb
import generate_months_module
import os
date_tag = '2000/2000/2009/09'
tree_location = '/Users/kelly/Documents/projects/komm/data/directory-tree/'
def iterateOverMonths(date_tag, x):
if x <= 0:
return_string = 'no dates found'
return return_string
else:
new_date = generate_months_module.handleDateShifts(date_tag)[1]
print '\tNEW DATE after calling handleDateShifts' + new_date
full_path = tree_location + '/' + new_date
if checkDirectoryExistance(full_path) == True:
print '\t'+ full_path + ' is a real path'
return full_path
else:
print 'dir does not exist'
iterateOverMonths(new_date, x-1)
def checkDirectoryExistance(dir_path):
"check if a directory exists, return true or false"
if os.path.isdir(dir_path) == True:
return True
else:
return False
print iterateOverMonths(date_tag, 6)
generate_months_module.handleDateShifts应该只是获取前一个月并返回它。 (这适用于其他测试用例,所以我非常怀疑问题在这里!)
我的输出是:
6
NEW DATE after calling handleDateShifts2000/2000/2009/08
dir does not exist
5
NEW DATE after calling handleDateShifts2000/2000/2009/07
dir does not exist
4
NEW DATE after calling handleDateShifts2000/2000/2009/06
/Users/kelly/Documents/projects/komm/data/directory-tree/2000/2000/2009/06 is a real path
returning full path
None
当我在“return full_path”之前使用pdb.set_trace()时,似乎再次调用该函数DESPITE,IF子句为True,因此写入我想要返回的“full_path”变量。
为什么不返回“/ Users / kelly / Documents / projects / komm / data / directory-tree / 2000/2000/2009/06”路径?
如果有人感兴趣并希望重新创建这个,那么handleDateShifts函数如下(道歉,它有点乱):
def handleDateShifts(corpus_date_string):
"get background corpus date strings ALSO call this function if month does not exist and need to go back even further"
century, decade, year, month = corpus_date_string.split('/')
if month == '01' or month == '02':
#handle date boundaries which can affect year, decade and cent
background_mo_1 = '11'
background_mo_2 = '12'
millenium_shift = re.search('[1-9][0][0][0]$', year)
century_shift = re.search('[1-9][0][0]$', year)
decade_shift = re.search('[1-9][0]$',year)
if century_shift or millenium_shift:
century = int(year) - 100
decade = int(year) - 10
year = int(year) - 1
elif decade_shift:
decade = int(year) - 10
year = int(year) - 1
elif not decade_shift and not century_shift:
year = int(year) - 1
background_1_string = str(century) +'/'+ str(decade) +'/'+ str(year) +'/'+ str(background_mo_1)
background_2_string = str(century) +'/'+ str(decade) +'/'+ str(year) +'/'+ str(background_mo_2)
else: #the cent/dec/year can stay the same
background_mo_1 = int(month) - 2
background_mo_2 = int(month) - 1
if len(str(background_mo_1)) == 1:
background_mo_1 = '0' + str(background_mo_1)
if len(str(background_mo_2)) == 1:
background_mo_2 = '0' + str(background_mo_2)
background_1_string = str(century) +'/'+ str(decade) +'/'+ str(year) +'/'+ str(background_mo_1)
background_2_string = str(century) +'/'+ str(decade) +'/'+ str(year)+'/'+ str(background_mo_2)
return background_1_string, background_2_string
答案 0 :(得分:1)
您不会在此分支中返回任何内容(结果会丢失):
else:
print 'dir does not exist'
iterateOverMonths(new_date, x-1)
如果函数在没有显式return <smth>
的情况下运行,则返回None
。