Python csv.DictReader:解析字符串? [英] Python csv.DictReader: parse string?

问题描述

我正在直接使用requests从URL下载CSV文件.

I am downloading a CSV file directly from a URL using requests.

如何用csv.DictReader解析结果字符串?

How can I parse the resulting string with csv.DictReader?

现在我有这个了

r = requests.get(url)
reader_list = csv.DictReader(r.text)
print reader_list.fieldnames
for row in reader_list:
    print row

但是我只是得到['r']作为fieldnames的结果，然后得到来自print row的各种奇怪的东西.

But I just get ['r'] as the result of fieldnames, and then all kinds of weird things from print row.

推荐答案

来自 ，csv.reader或csv.DictReader的第一个参数是csvfile-

From documentation of csv , the first argument to csv.reader or csv.DictReader is csvfile -

csvfile可以是任何支持迭代器协议的对象，并且每次调用next()方法时都会返回一个字符串-文件对象和列表对象都适用

csvfile can be any object which supports the iterator protocol and returns a string each time its next() method is called — file objects and list objects are both suitable

在您将字符串作为csv.DictReader()的直接输入的情况下，对它的next()调用仅提供一个字符，因此成为标题，然后持续调用next()以获取每一行.

In your case when you give the string as the direct input for the csv.DictReader() , the next() call on it only provides a single character, and hence that becomes the header, and then next() is continuously called to get each row.

因此，您需要提供字符串的内存流(使用StringIO)或行列表(使用splitlines)

Hence, you need to either provide a in-memory stream of the string (Using StringIO) or a list of lines (using splitlines)

您可以使用 io.StringIO() ，然后在csv.DictReader中使用它.示例/演示-

You can use io.StringIO() and then use it in csv.DictReader . Example/Demo -

>>> import csv
>>> s = """a,b,c
... 1,2,3
... 4,5,6
... 7,8,9"""
>>> import io
>>> reader_list = csv.DictReader(io.StringIO(s))
>>> print reader_list.fieldnames
['a', 'b', 'c']
>>> for row in reader_list:
...     print row
... 
{'a': '1', 'c': '3', 'b': '2'}
{'a': '4', 'c': '6', 'b': '5'}
{'a': '7', 'c': '9', 'b': '8'}

---

或者如注释中所示，您可以先分割行，然后再输入csv.DictReader.示例/演示-

---

Or as indicated in the comments , you can split the lines before giving as input to csv.DictReader . Example/Demo -

>>> reader_list = csv.DictReader(s.splitlines())
>>> print reader_list.fieldnames
['a', 'b', 'c']
>>> for row in reader_list:
...     print row
... 
{'a': '1', 'c': '3', 'b': '2'}
{'a': '4', 'c': '6', 'b': '5'}
{'a': '7', 'c': '9', 'b': '8'}

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