我从数据库中获取一些数据，当我尝试将查询结果打印到tkinter Text Widget时，它显示错误：
statTextField.insert(INSERT,("{0:28}{1:40}{2:20}{3:20}\n".format(row[0],row[1],row[2],row[3])))
TypeError: non-empty format string passed to object.__format__
查询的某些结果是正常数字，但是有空记录，它们是实际字符串“无”。当我只打印带有 jquartz_fired_triggers 表中的统计数据的记录时，没有问题。打印“空”记录时出现错误
jquartz_cron_triggers | |
jquartz_fired_triggers 0.50000000000000000000|0.00000000000000000000|0.50000000000000000000
jquartz_job_details | |
以下是负责在tkinter Text小部件中打印所有内容的代码：
z3.execute("""SELECT relname,
case
when (n_tup_ins + n_tup_upd + n_tup_del) > 0 then
cast(n_tup_ins AS numeric) / (n_tup_ins + n_tup_upd + n_tup_del)
else
null
end AS ins_pct,
case
when (n_tup_ins + n_tup_upd + n_tup_del) > 0 then
cast(n_tup_upd AS numeric) / (n_tup_ins + n_tup_upd + n_tup_del)
else
null
end AS upd_pct,
case
when (n_tup_ins + n_tup_upd + n_tup_del) > 0 then
cast(n_tup_del AS numeric) / (n_tup_ins + n_tup_upd + n_tup_del)
else
null
end AS del_pct
FROM pg_stat_user_tables
ORDER BY relname;""")
if(bool(z3.rowcount) == True):
statTextField.insert(INSERT, "\n\n\nSTATYSTYKI INS/UPD/DEL\nRELNAME | INSERTED | UPDATED | DELETED\n")
for row in z3.fetchall():
statTextField.insert(INSERT,("{0:28}{1:40}{2:20}{3:20}\n".format(row[0],row[1],row[2],row[3]))) # <-------- Problem is here
代码应该能够打印数字数据和空记录。你知道怎么做吗？
P.S。我发现有类似问题的问题，但没有找到有关如何修复我的代码的有用信息