这段代码在以下情况下工作正常cur.execute()
and db.commit()
行被注释掉;即,如果我所做的只是打印查询,则该程序将运行 n 行。问题似乎出现在这里:
player_categories_statistics = cur.fetchone()
player_id = player_categories_statistics[0]
当我尝试插入结果时,我得到:
Traceback (most recent call last):
File "test2.py", line 72, in <module>
meat = meatgrind(league_name, categories_measurement_statistics)
File "test2.py", line 32, in meatgrind
player_id = int(player_categories_statistics[0])
TypeError: 'NoneType' object is not subscriptable
代码:
import sys
import MySQLdb
import string
db = MySQLdb.connect()
cur = db.cursor('localhost','me',XXXXX,'testdb')
def meatgrind(league_name,categories_measurement_statistics):
# a varied range of different categories can be used
# 1. list categories
categories = []
categories_string = "player_id"
categories_string_newtable = "meatgrinded_player_id, player_id"
for category in categories_measurement_statistics:
categories_string += ", " + category[0]
categories_string_newtable += ", " + category[0]
# 2. get players and statistics
query = "SELECT %s FROM players" % (categories_string)
cur.execute("%s" % (query))
# rowcount = int(cur.rowcount)
rowcount = 2 #hard-coded for debugging
# 3. meatgrind one player at a time
meatgrinded_player_id = 1
for i in range(rowcount):
player_categories_statistics = cur.fetchone()
player_id = player_categories_statistics[0]
#4. grind a category statistic
meatgrindings_string = "%d, %d" % (meatgrinded_player_id, player_id)
index = 1
for category in categories_measurement_statistics:
# SOME MATH HERE resulting in player_meatgrindings
meatgrindings_string += ", %0.4f" % player_meatgrindings
query = """INSERT INTO sometable (%s) VALUES (%s)""" % (categories_string_newtable, meatgrindings_string)
cur.execute("%s" % (query))
db.commit()
meatgrinded_player_id += 1
league_name = 'test'
categories_measurement_statistics = (('H', 156.3, 19.643093216474604), ('HR', 21.3, 9.003147597738618), ('SB', 13.25, 16.041179646286754))
meat = meatgrind(league_name, categories_measurement_statistics)