Question

下午，

我在使用SQLite到CSV python脚本时遇到了一些麻烦。我已经搜索得很高，我已经搜索到了一个答案，但没有一个对我有用，或者我的语法有问题。

我想替换SQLite数据库中不属于ASCII表（大于128）的字符。

以下是我一直使用的脚本：

#!/opt/local/bin/python
import sqlite3
import csv, codecs, cStringIO

class UnicodeWriter:
    """
    A CSV writer which will write rows to CSV file "f", 
    which is encoded in the given encoding.
    """

    def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
        # Redirect output to a queue
        self.queue = cStringIO.StringIO()
        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()

    def writerow(self, row):
        self.writer.writerow([unicode(s).encode("utf-8") for s in row])
        # Fetch UTF-8 output from the queue ...
        data = self.queue.getvalue()
        data = data.decode("utf-8")
        # ... and reencode it into the target encoding
        data = self.encoder.encode(data)
        # write to the target stream
        self.stream.write(data)
        # empty queue
        self.queue.truncate(0)

    def writerows(self, rows):
        for row in rows:
            self.writerow(row)

conn = sqlite3.connect('test.db')

c = conn.cursor()

# Select whichever rows you want in whatever order you like
c.execute('select ROWID, Name, Type, PID from PID')

writer = UnicodeWriter(open("ProductListing.csv", "wb"))

# Make sure the list of column headers you pass in are in the same order as your SELECT
writer.writerow(["ROWID", "Product Name", "Product Type", "PID", ])
writer.writerows(c)

我试图添加'替换'，如此处所示，但有相同的错误。 Python: Convert Unicode to ASCII without errors for CSV file

错误是UnicodeDecodeError。

Traceback (most recent call last):
  File "SQLite2CSV1.py", line 53, in <module>
    writer.writerows(c)
  File "SQLite2CSV1.py", line 32, in writerows
    self.writerow(row)
  File "SQLite2CSV1.py", line 19, in writerow
    self.writer.writerow([unicode(s).encode("utf-8") for s in row])
UnicodeDecodeError: 'ascii' codec can't decode byte 0xa0 in position 65: ordinal not in range(128)

显然我希望代码足够健壮，如果它遇到这些边界之外的字符，它会用“？”等字符替换它。（\ X3F）。

有没有办法在UnicodeWriter类中执行此操作？我可以通过一种方式使代码健壮，不会产生这些错误。

非常感谢您的帮助。

Answer 1

如果您只想编写ASCII CSV，只需使用股票csv.writer()即可。要确保传递的所有值都是ASCII，请使用encode('ascii', errors='replace')。

示例：

import csv

rows = [
  [u'some', u'other', u'more'],
  [u'umlaut:\u00fd', u'euro sign:\u20ac', '']
]

with open('/tmp/test.csv', 'wb') as csvFile:
    writer = csv.writer(csvFile)
    for row in rows:
        asciifiedRow = [item.encode('ascii', errors='replace') for item in row]
        print '%r --> %r' % (row, asciifiedRow)
        writer.writerow(asciifiedRow)

控制台输出为：

[u'some', u'other', u'more'] --> ['some', 'other', 'more']
[u'umlaut:\xfd', u'euro sign:\u20ac', ''] --> ['umlaut:?', 'euro sign:?', '']

生成的CSV文件包含：

some,other,more
umlaut:?,euro sign:?,

Answer 2

通过访问unix环境，这里有什么对我有用

sqlite3.exe a.db .dump > a.sql;
tr -d "[\\200-\\377]" < a.sql > clean.sql;
sqlite3.exe clean.db < clean.sql;

（它不是一个python解决方案，但也许它会帮助其他人，因为它的简洁。这个解决方案STRIPS OUT所有非ascii字符，不会尝试替换它们。）

Python - SQLite到CSV Writer错误 - 未解析ASCII值

2 个答案: