python - 如何做 while() "pythonic way"

Question

我想这样做:

from django.db import connection

cursor = connection.cursor()
cursor.execute("PRAGMA table_info(ventegroupee)")
while row = cursor.fetchone():
    print(row)

我明白了:

  File "<input>", line 1
    while row = cursor.fetchone():
              ^
SyntaxError: invalid syntax

这样做的“pythonic”方式是什么？

Answer 1

您根本不必使用 while 循环，因为游标是可迭代的:

for row in cursor:
    print(row)

来自 Django documentation 的“连接和游标”部分:

connection and cursor mostly implement the standard Python DB-API described in PEP 249 — except when it comes to transaction handling.

来自提到的PEP 249 :

Cursor.next()

Return the next row from the currently executing SQL statement using the same semantics as .fetchone()

Cursor.__iter__()

Return self to make cursors compatible to the iteration protocol