找不到名为游标的模块

Question

我刚刚在我的 VPS 上安装了 PyMySQL，安装似乎没有任何问题。

为确保一切正常，我尝试执行我在their documentation. 中找到的以下脚本

Python 2.7.5 和 Python 3.6.5

Server version: 10.1.34-MariaDB MariaDB Server

import pymysql.cursors

# Connect to datebase
con = pymysql.connect(host='localhost',
                    user='dbuser',
                    password='dbpass',
                    db='dbname',
                    charset='utf8mb4',
                    cursorclass=pymysql.cursor.DictCursor)

try:
    with con.cursor() as cursor:
        # Create new record
        sql = "INSERT INTO `test` (`idx`, `title`, `description`, `category`) VALUES (%s, %s, %s, %s)"
        cursor.execute(sql, (1, 'Fake Title', 'Fake description about a fake post.', 'WELLNESS'))

    with con.cursor() as cursor:
        # Read a single record
        sql = "SELECT `idx`, `title` FROM `test` WHERE `idx`=%s"
        cursor.execute(sql, ('1'))
        result = cursor.fetchone()
finally:
    with open('dbText.txt', 'w') as f:
        f.write('%s'.format(result))
        con.close()

但是，我收到了一个ImportError，上面写着No module found named cursors。

[root@host public_html]# python pymysql.py

Traceback (most recent call last):
    File "pymysql.py", line 1, in <module>
        import pymysql.cursors
    File "/home/bldsprt/public_html/pymysql.py", line 1, in <module>
        import pymysql.cursors
ImportError: No module named cursors

[root@host public_html]# python3.6 pymysql.py
Traceback (most recent call last):
  File "pymysql.py", line 1, in <module>
    import pymysql.cursors
  File "/home/bldsprt/public_html/pymysql.py", line 1, in <module>
    import pymysql.cursors
ModuleNotFoundError: No module named 'pymysql.cursors'; 'pymysql' is not a package

当我尝试重新安装时，表明pymysql已经安装。

[root@host public_html]# pip install pymysql
Requirement already satisfied: pymysql in /usr/local/lib/python3.6/site-packages (0.9.0)
Requirement already satisfied: cryptography in /usr/local/lib/python3.6/site-packages (from pymysql) (2.2.2)
Requirement already satisfied: idna>=2.1 in /usr/local/lib/python3.6/site-packages (from cryptography->pymysql) (2.7)
Requirement already satisfied: six>=1.4.1 in /usr/local/lib/python3.6/site-packages (from cryptography->pymysql) (1.11.0)
Requirement already satisfied: cffi>=1.7; platform_python_implementation != "PyPy" in /usr/local/lib/python3.6/site-packages (from cryptography->pymysql) (1.11.5)
Requirement already satisfied: asn1crypto>=0.21.0 in /usr/local/lib/python3.6/site-packages (from cryptography->pymysql) (0.24.0)
Requirement already satisfied: pycparser in /usr/local/lib/python3.6/site-packages (from cffi>=1.7; platform_python_implementation != "PyPy"->cryptography->pymysql) (2.18)

需要单独安装cursors模块吗？

任何帮助都会很大！

Answer 1

堆栈跟踪的这一部分揭示了问题：

    File "/home/bldsprt/public_html/pymysql.py", line 1, in <module>
          import pymysql.cursors
ImportError: No module named cursors

您已将用于测试的文件命名为“pymysql.py”——因此，Python 尝试从同一个文件中获取游标模块。如果您将文件重命名为其他名称，它应该能够加载正确的库文件，只要通过 pip2/pip2.7 安装 pymysql（似乎您系统上的 pip 默认为 Python 3 安装）。

另外，从包和文档本身来看，我认为当你初始化 MySQL 连接对象（con）时，它应该使用pymysql.cursors.DictCursor（游标，而不是游标）作为游标类。