在编写python函数时，无意中发现一个问题：python中的变量不能以数字打头，以下函数中定义了一个变量3_num_varchar，执行时报错。
函数如下：
def database_feild_varchar_trans(in_feild):
”’
transfer the feild if varchar then 3times lang else no transfer
”’
feild_split = in_feild.split(‘ ‘)
is_varchar = feild_split[1].find(‘varchar’)
if is_varchar >= 0 :
num_varchar = feild_split[1].replace(‘varchar’,”).replace(‘(‘,”).replace(‘)’,”)
print (num_varchar)
3_num_varchar = num_varchar*3
feild_split[1] = feild_split[1].replace(str(num_varchar),str(3_num_varchar))
return feild_split
else:
print (‘the feild type is not varchar’)
return feild_split
报错信息如下：
>>> runfile(‘e:/procedure/python/projects/others/table_test.py’, wdir=’e:/procedure/python/projects/others’)
traceback (most recent call last):
file “”, line 1, in
file “d:\python33\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py”, line 699, in runfile
execfile(filename, namespace)
file “d:\python33\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py”, line 88, in execfile
exec(compile(open(filename, ‘rb’).read(), filename, ‘exec’), namespace)
file “e:/procedure/python/projects/others/table_test.py”, line 20
3_num_varchar = int(num_varchar)*3
^
syntaxerror: invalid syntax
将变量3_num_varchar改为num_varchar_3，运行成功，程序改为如下：
import os
import sys
str1=’aaa varchar(10)’
def database_feild_varchar_trans(in_feild):
”’
transfer the feild if varchar then 3times lang else no transfer
”’
feild_split = in_feild.split(‘ ‘)
is_varchar = feild_split[1].find(‘varchar’)
if is_varchar >= 0 :
num_varchar = feild_split[1].replace(‘varchar’,”).replace(‘(‘,”).replace(‘)’,”)
print (num_varchar)
num_varchar_3 = num_varchar*3
feild_split[1] = feild_split[1].replace(str(num_varchar),str(num_varchar_3))
return feild_split
else:
print (‘the feild type is not varchar’)
return feild_split
print (database_feild_varchar_trans(str1))
运行结果：
>>> runfile(‘e:/procedure/python/projects/others/table_test.py’, wdir=’e:/procedure/python/projects/others’)
the feild type is not varchar
[‘aaa’, ‘varchar(10)’]
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