列表索引必须是整数或切片，而不是 str

我有两个列表，我想合并到一个单一的数组，最后把它放在一个 csv 文件。

如何避免这个错误:

def fill_csv(self, array_urls, array_dates, csv_file_path):
result_array = []
array_length = str(len(array_dates))


# We fill the CSV file
file = open(csv_file_path, "w")
csv_file = csv.writer(file, delimiter=';', lineterminator='\n')


# We merge the two arrays in one


for i in array_length:
result_array[i][0].append(array_urls[i])
result_array[i][1].append(array_dates[i])
i += 1


csv_file.writerows(result_array)

然后得到:

  File "C:\Users\--\gcscan.py", line 63, in fill_csv
result_array[i][0].append(array_urls[i])
TypeError: list indices must be integers or slices, not str

我的计数怎么工作？

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最佳答案

First, array_length should be an integer and not a string:

array_length = len(array_dates)

Second, your for loop should be constructed using range:

for i in range(array_length):  # Use `xrange` for python 2.

Third, i will increment automatically, so delete the following line:

i += 1

Note, one could also just zip the two lists given that they have the same length:

import csv


dates = ['2020-01-01', '2020-01-02', '2020-01-03']
urls = ['www.abc.com', 'www.cnn.com', 'www.nbc.com']


csv_file_patch = '/path/to/filename.csv'


with open(csv_file_patch, 'w') as fout:
csv_file = csv.writer(fout, delimiter=';', lineterminator='\n')
result_array = zip(dates, urls)
csv_file.writerows(result_array)
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I had same error and the mistake was that I had added list and dictionary into the same list (object) and when was iterating over the list of dictionaries and hit a list type object then I would get this error since I was trying to access keys within each dictionary.

I had to made sure that I only added dictionary objects to that list

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Follow up on Abdeali Chandanwala answer above (couldn't comment because rep<50) -

TL;DR: I was trying to iterate through a list of dictionaries incorrectly by focusing to iterate over the keys in the dictionary but instead had to iterate over the dictionaries themselves!

I came across the same error while having a structure like this:

{
"Data":[
{
"RoomCode":"10",
"Name":"Rohit",
"Email":"rohit@123.com"
},
{
"RoomCode":"20"
"Name":"Karan",
"Email":"karan@123.com"
}
]
}

And I was trying to append the names in a list like this-

Same error received

Fixed it by-

Fixed the error

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I received this error overloading a function in python where one function wrapped another:

def getsomething(build_datastruct_inputs : list[str]) -> int:
# builds datastruct and calls getsomething
return getsomething(buildit(build_datastruct_inputs))


def getsomething(datastruct : list[int]) -> int:
# code
# received this error on first use of 'datastruct'

Fix was to not overload and use unique method name.

def getsomething_build(build_datastruct_inputs : list[str]) -> int:
# builds datastruct and calls getsomething
return getsomething_ds(buildit(build_datastruct_inputs))


def getsomething_ds(datastruct : list[int]) -> int:
# code
# works fine again regardless of whether invoked directly/indirectly

Another fix could be to use python multipledispatch package which will let you overload and figures this out for you.

Was a bit confusing because where the error was occuring (nor message) corresponded to what cause was. I thought I had seen that python supported overloading natively but now I've learned it's implementation requires more work from the user.

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In my case I was trying to change the value of a dict key but since my dict was there in a for loop and was getting changed to type list i was getting the same error.

for value in source_list:
my_dict['my_key']=some_val
dict=list(mydict)
exctraction0 = dict[0]

i resolved it by making sure the type of dict remains the same by making a deepcopy and re-initializing after every iteration(that is what the use-case was all about).

copy_dict = copy.deepcopy(my_dict)
for value in source_list:
my_dict =copy.deepcopy(copy_dict)
my_dict['my_key']=some_val
dict=list(mydict)
exctraction0 = dict[0]

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