<p>你的程序中有很多小错误。让我试着列出它们:</p>
<ul>
<li><code>re.findall</code>返回一个列表,但您似乎将其视为单个字符串。尝试<code>email = email[0]</code>只考虑列表的第一个元素。在</li>
<li>您的第一个<code>SELECT</code>语句有<code>(email)</code>。将一个项目放在括号内不会使其成为元组。请尝试<code>(email,)</code>或{<cd6>}。在</li>
<li>在<code>for</code>循环之后的<code>if</code>将在<code>for</code>循环的每次迭代中出现,因此它必须缩进一个句点。在</li>
<li><code>if</code>的正文不能为空。取消该操作的注释,或将其更改为<code>pass</code>。在</li>
<li>最后一个<code>for</code>循环的主体需要缩进一个句点。在</li>
<li>出于对堆栈溢出阅读器的礼貌,请复制粘贴整个独立程序,而不仅仅是代码片段。在</li>
</ul>
<p>以下是我解决问题后的程序:</p>
<pre><code>import sqlite3
import re
conn = sqlite3.connect(':memory:')
cur = conn.cursor()
cur.execute('''
DROP TABLE IF EXISTS Counts''')
cur.execute('''
CREATE TABLE Counts (email TEXT, count INTEGER)''')
fname = raw_input('Enter file name: ')
if ( len(fname) < 1 ) : fname = 'mbox-short.txt'
fh = open(fname)
for line in fh:
if not line.startswith('From: ') : continue
line = line.rstrip()
email = re.findall('@(\S+[a-zA-Z]+)', line)
email = email[0]
cur.execute('SELECT count FROM Counts WHERE email = ? ', (email,))
row = cur.fetchone()
if row is None:
cur.execute('''INSERT INTO Counts (email, count)
VALUES ( ?, 1 )''', ( email, ) )
else :
cur.execute('UPDATE Counts SET count=count+1 WHERE email = ?',
(email, ))
# This statement commits outstanding changes to disk each
# time through the loop - the program can be made faster
# by moving the commit so it runs only after the loop completes
conn.commit()
# https://www.sqlite.org/lang_select.html
sqlstr = 'SELECT email, count FROM Counts ORDER BY count DESC LIMIT 10'
print
print "Counts:"
for row in cur.execute(sqlstr) :
print str(row[0]), row[1]
cur.close()
</code></pre>