我目前正在学习如何使用visualstudios和sqlite用python修改数据。我的任务是计算在一个文件中发现电子邮件的次数,并以一种方式组织它们,然后对每封电子邮件进行计数。然后我必须将它们作为一个名为Counts的表输入到SQLite中,该表有两行(org,count)。我编写了一个代码,运行程序并将其输出到visualstudios的输出屏幕上,但不输出到数据库。你知道吗
这是我的程序:
import sqlite3
conn = sqlite3.connect('database3.db')
cur = conn.cursor()
cur.execute('DROP TABLE IF EXISTS Counts')
cur.execute('''CREATE TABLE Counts (email TEXT, count INTEGER)''')
#cur.execute("INSERT INTO Counts Values('mlucygray@gmail.com',1)")
# Save (commit) the changes
conn.commit()
fname = 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
pieces = line.split()
email = pieces[1]
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,))
cur.execute('SELECT * FROM Counts')
# https://www.sqlite.org/lang_select.html
sqlstr = 'SELECT email, count FROM Counts ORDER BY count DESC LIMIT 10'
conn.commit()
for row in cur.execute(sqlstr):
print(str(row[0]), row[1])
conn.commit()
cur.close()
click here for the link to the output of the above code
谢谢你的建议
您需要使用insert/update提交更改,而不需要在执行select语句后提交。你知道吗
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