Python variables cannot be detailed with numbers.

Python variables cannot be detailed with numbers.

When writing a python function, you may accidentally find a problem: the variable in python cannot be prefixed with a number. The following function defines the variable 3_num_varchar, and an error is returned when executing the command.

The function is as follows:

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

The error message is as follows:

>>> 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: Replace the variable 3_num_varchar with num_varchar_3. The program runs successfully as follows: import osimport sysstr1 = 'aaa varchar (10) 'def evaluate (in_feild ): '''transfer the feild if varchar then 3 times 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 ))

Running result:

>>> runfile('E:/procedure/python/projects/others/table_test.py', wdir='E:/procedure/python/projects/others')The feild type is not varchar['aaa', 'varchar(10)']

The above python variable cannot be explained in the beginning with a number, that is, all the content shared by the editor. I hope to give you a reference and support for the help house.