如何以正确的方式连接到Python中的MySQL数据库？

Question

update; hence to the kind and helpful replies of two great users here i did the following

hello dear bryn many thanks i erased the db cpan and runned the programme again see the results:

martin@linux-70ce:~/perl> python cpan_100.py
Traceback (most recent call last):
  File "cpan_100.py", line 45, in <module>
    user = User.create(name=entry["name"], cname=entry["cname"],
TypeError: string indices must be integers, not str

well this is somewhat difficult - why do i get these results!!?`

here the original posting

fairly new to python and to programming too.

I'm trying to connect to a MySQL database on Amazon's RDS using peewee and I can't get it to work. I'm new to databases so I'm probably doing something stupid, but this is what I'm trying: well i tried to get connection to a database in python with peewee but at a certain point the programme fails.

import urllib
import urlparse
import re
# import peewee
import json
from peewee import *
#from peewee import MySQLDatabase ('cpan', user='root',passwd='rimbaud') 
db = MySQLDatabase('cpan', user='root',passwd='rimbaud') 

class User(Model):
    name = TextField()
    cname = TextField()
    email = TextField()
    url = TextField()

    class Meta:
        database = db # this model uses the cpan database

User.create_table() #ensure table is created

url = "http://search.cpan.org/author/?W"
html = urllib.urlopen(url).read()
for lk, capname, name in re.findall('<a href="(/~.*?/)"><b>(.*?)</b></a><br/><small>(.*?)</small>', html):
    alk = urlparse.urljoin(url, lk)
    data = { 'url':alk, 'name':name, 'cname':capname }
    phtml = urllib.urlopen(alk).read()
    memail = re.search('<a href="mailto:(.*?)">', phtml)
    if memail:
        data['email'] = memail.group(1)

# data = json.load('email') #your json data file here
for entry in data: #assuming your data is an array of JSON objects
    user = User.create(name=entry["name"], cname=entry["cname"],
        email=entry["email"], url=entry["url"])
    user.save()

i get back the following results

martin@linux-70ce:~/perl> python cpan_100.py
Traceback (most recent call last):
  File "cpan_100.py", line 27, in <module>
    User.create_table() #ensure table is created
  File "build/bdist.linux-i686/egg/peewee.py", line 3078, in create_table                                                                                                           
  File "build/bdist.linux-i686/egg/peewee.py", line 2471, in create_table                                                                                                           
  File "build/bdist.linux-i686/egg/peewee.py", line 2414, in execute_sql                                                                                                            
  File "build/bdist.linux-i686/egg/peewee.py", line 2283, in __exit__                                                                                                               
  File "build/bdist.linux-i686/egg/peewee.py", line 2406, in execute_sql                                                                                                            
  File "/usr/lib/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute                                                                                                  
    self.errorhandler(self, exc, value)                                                                                                                                             
  File "/usr/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler                                                                                   
    raise errorclass, errorvalue                                                                                                                                                    
peewee.OperationalError: (1050, "Table 'user' already exists")                                                                                                                      
martin@linux-70ce:~/perl>

if you can help me i would e very glad! Thanks for any and all help

greetings

Answer 1

It looks like it connects to your database properly but fails because the line:

User.create_table() #ensure table is created

tries to create a table then fails because a table already exists, hence the error message:

peewee.OperationalError: (1050, "Table 'user' already exists") 

Try commenting it out:

#User.create_table()