将两个csv文件合并到字典列表中
将两个csv文件合并到字典列表中
提问于 2019-05-31 00:32:54
我有一个任务要做，我被卡住了，因为无论我做什么，它似乎都不起作用。
所以我必须保存csv文件。首先调用persons_file，它包含标题行: id、姓名、姓氏。以及包含id、person_id、site的visits_file。我必须编写一个名为merge的函数，它将文件作为参数(都是StrionIO类型)并返回每个用户的访问次数的字典列表：
[ {
"id": (person's id),
"name": (person's name),
"surname": (person's surname),
"visits": (number of visits)
} ]我想出了这个，我不知道我的错误在哪里。
import io
def merge(persons_file,visits_file):
line_counter = 0
return_list = []
list_of_person_ids = []
visits = 0
for row in visits_file:
if line_counter == 0:
line_counter+=1
continue
list_of_person_ids.append(row.split(',')[1])
line_counter = 0
for row in persons_file:
if line_counter == 0:
line_counter+=1
continue
help_dict = {}
split_row = row.split(',')
help_dict['id'] = split_row[0]
help_dict['name'] = split_row[1]
help_dict['surname'] = split_row[2][:len(split_row[2])-1]
if split_row[0] in list_of_person_ids:
visits = list_of_person_ids.count(split_row[0])
help_dict['visits'] = str(visits)
return_list.append(help_dict)
visits=0
return return_list
file1 = open('persons_file.csv' , mode='r')
file2 = open('visits_file.csv' , mode='r')
persons_file_arg = io.StringIO(file1.read())
visits_file_arg = io.StringIO(file2.read())
list_of_visits = merge(persons_file_arg,visits_file_arg)
for i in list_of_visits:
print(i)
file1.close()
file2.close()如果有人能帮我，我会很高兴的。
回答 1
Stack Overflow用户
发布于 2019-05-31 01:41:23
问题出在哪里？是输出不是你所期望的，还是你得到了一个异常？您的代码看起来应该可以达到您想要的结果，但我有几个建议可以简化事情。
- 查看
collections.Counter，然后可以调用count_of_visits_by_person_id = Counter(list_of_person_ids)获得以下形式的结果：{person_id: number_of_visits, ...}。然后，您可以使用它在下一个for循环中简单地查找访问次数。例如：
from collections import Counter
...
count_of_visits_by_person_id = Counter(list_of_person_ids)
for row in persons_file:
if line_counter == 0:
line_counter += 1
continue
help_dict = {}
split_row = row.split(',')
help_dict['id'] = split_row[0]
help_dict['name'] = split_row[1]
help_dict['surname'] = split_row[2][:-1]
# [:len(split_row[2]) - 1] is equivalent to [:-1]
# I assume you are stripping whitespace from the right side,
# which can also be accomplished using split_row[2].rstrip()
if split_row[0] in count_of_visits_by_person_id:
visits = count_of_visits_by_person_id[split_row[0]]
else:
visits = 0
help_dict['visits'] = str(visits)
return_list.append(help_dict)- 通常更简单、更安全的打开文件的方法是使用
with语句。下面是一个例子：
with open('visits_file.csv', mode='r') as visits_file:
row = visits_file.readline()
while row:
row = visits_file.readline() # Skips the first line
list_of_person_ids.append(row.split(',')[1])页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/56382173
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