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 "<stdin>", line 1, in <module> 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 osimport sysstr1='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_splitprint (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)']

以上这篇python变量不能以数字打头详解就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。