Python 3.3 CSV.Writer 写入额外的空白行
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Python 3.3 CSV.Writer writes extra blank rows
提问by Nyxynyx
Using Python 3.3 on Windows 8, when writing to a CSV file, I get the error TypeError: 'str' does not support the buffer interfaceand "wb"flag was used. However when only the "w"flag was used, I get no errors, but every row is separated by a blank row!
在 Windows 8 上使用 Python 3.3，写入 CSV 文件时，出现错误TypeError: 'str' does not support the buffer interface并使用了"wb"标志。然而，当只使用"w"标志时，我没有得到任何错误，但每一行都被一个空行分隔！
Problem Writing
问题写作
Code
代码
test_file_object = csv.reader( open("./files/test.csv", 'r') )
next(test_file_object )
with open("./files/forest.csv", 'wb') as myfile:
open_file_object = csv.writer( open("./files/forest.csv", 'wb') )
i = 0
for row in test_file_object:
row.insert(0, output[i].astype(np.uint8))
open_file_object.writerow(row)
i += 1
Error
错误
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-121-8cbb94f602a8> in <module>()
8 for row in test_file_object:
9 row.insert(0, output[i].astype(np.uint8))
---> 10 open_file_object.writerow(row)
11 i += 1
TypeError: 'str' does not support the buffer interface
Problem Reading
问题阅读
When reading, I cant seem to use the "rb"flags so it will give the error iterator should return strings, not byteswhen trying to ignore the first row (headers).
阅读时，我似乎无法使用"rb"标志，因此iterator should return strings, not bytes在尝试忽略第一行（标题）时会出现错误。
Code
代码
csv_file_object = csv.reader(open('files/train.csv', 'rb'))
header = next(csv_file_object)
train_data = []
for row in csv_file_object:
train_data.append(row)
train_data = np.array(train_data)
Error
错误
Error Traceback (most recent call last)
<ipython-input-10-8b13d1956432> in <module>()
1 csv_file_object = csv.reader(open('files/train.csv', 'rb'))
----> 2 header = next(csv_file_object)
3 train_data = []
4 for row in csv_file_object:
5 train_data.append(row)
Error: iterator should return strings, not bytes (did you open the file in text mode?)
回答by AdriVelaz
Hi this may help you.
你好这可能对你有帮助。
First Problem,
第一个问题，
change
改变
with open("./files/forest.csv", 'wb') as myfile:
open_file_object = csv.writer( open("./files/forest.csv", 'wb') )
to
到
with open("./files/forest.csv", 'w+') as myfile:
open_file_object = csv.writer( open("./files/forest.csv", 'w+') )
Second problem:
第二个问题：
Same exact thing, except change to r+
完全相同，除了更改为 r+
If that doesn't work, you can always just use this to strip out all the blank rows after it's created.
如果这不起作用，您可以随时使用它在创建后删除所有空白行。
for row in csv:
if row or any(row) or any(field.strip() for field in row):
myfile.writerow(row)
Also, a little lesson. "rb" stands for reading bytes, essentially think of it as reading an integer only. I'm not to sure what's the content of your csv; however, there must be strings in that csv.
另外，一点教训。“rb”代表读取字节，本质上将其视为仅读取整数。我不确定你的 csv 的内容是什么；但是，该 csv 中必须有字符串。
This will help for future reference.
这将有助于将来参考。
The argument mode points to a string beginning with one of the following sequences (Additional characters may follow these sequences.):
参数 mode 指向以以下序列之一开头的字符串（其他字符可能跟在这些序列之后。）：
``r'' Open text file for reading. The stream is positioned at the
beginning of the file.
``r+'' Open for reading and writing. The stream is positioned at the
beginning of the file.
``w'' Truncate file to zero length or create text file for writing.
The stream is positioned at the beginning of the file.
``w+'' Open for reading and writing. The file is created if it does not
exist, otherwise it is truncated. The stream is positioned at
the beginning of the file.
``a'' Open for writing. The file is created if it does not exist. The
stream is positioned at the end of the file. Subsequent writes
to the file will always end up at the then current end of file,
irrespective of any intervening fseek(3) or similar.
``a+'' Open for reading and writing. The file is created if it does not
exist. The stream is positioned at the end of the file. Subse-
quent writes to the file will always end up at the then current
end of file, irrespective of any intervening fseek(3) or similar.
回答by pepr
The 'wb'mode was OK for Python 2. However, it is wrong in Python 3. In Python 3, the csv reader needs strings, not bytes. This way, you have to open it in text mode. However, the \nmust not be interpreted when reading the content. This way, you have to pass newline=''when opening the file:
该'wb'模式在 Python 2 中是可以的。但是，在 Python 3 中是错误的。在 Python 3 中，csv 读取器需要字符串，而不是字节。这样，您必须以文本模式打开它。但是，\n阅读内容时不得解释。这样，你newline=''在打开文件的时候就必须通过：
with open("./files/forest.csv", newline='') as input_file \
open('something_else.csv', 'w', newline='') as output_file:
writer = csv.writer(output_file)
...
If the file is not pure ASCII, you should also consider to add the encoding=...parameter.
如果文件不是纯ASCII，还应该考虑添加encoding=...参数。
