如何在Python中动态引用变量?
我有以下代码:如何在Python中动态引用变量?,python,Python,我有以下代码: PROJECT_ID = 'test' BQ_TABLE_NAME_CATEGORIES = 'categories' BQ_TABLE_NAME_MANUFACTURERS = 'manufacturers' list = [BQ_TABLE_NAME_CATEGORIES, BQ_TABLE_NAME_MANUFACTURERS] table_categories = PROJECT_ID + '.' + BQ_TABLE_NAME_CATEGORIES table_man
PROJECT_ID = 'test'
BQ_TABLE_NAME_CATEGORIES = 'categories'
BQ_TABLE_NAME_MANUFACTURERS = 'manufacturers'
list = [BQ_TABLE_NAME_CATEGORIES, BQ_TABLE_NAME_MANUFACTURERS]
table_categories = PROJECT_ID + '.' + BQ_TABLE_NAME_CATEGORIES
table_manufacturers = PROJECT_ID + '.' + BQ_TABLE_NAME_MANUFACTURERS
for table in list:
....
source_objects=['table_{0}'.format(table)] #reference to the correct var
....
但是,这会将字符串放入源对象中。我希望它引用变量(变量中保存的内容)
这意味着我真正想要的是与之相当的:
当table=BQ\u table\u NAME\u CATEGORIES
source_objects = [ table_categories ]
当table=BQ\u table\u NAME\u制造商时
source_objects = [ table_manufacturers ]
可以使用eval()函数将字符串转换为变量:
输出:
另外,正如评论中所指出的,您确实不应该覆盖列表,而应该使用mylist或其他任何内容如果我正确理解了您的问题,您要做的是将表\u类别
和表\u制造商
的值存储在名为源\u对象
的列表中。
假设表中的变量是全局变量
suffixes = [BQ_TABLE_NAME_CATEGORIES, BQ_TABLE_NAME_MANUFACTURERS]
source_objects = []
for s in suffixes:
source_objects.append(globals['table_{0}'.append(s)])
...
这会让你:
>>> source_objects
['test.categories', 'test.manufacturers']
如果表变量不是全局变量,请使用locals()
。请参见您是否试图在列表中获取表_categories
中的内容?还是只想引用它的字符串值?另外,重写内置的列表对象是不好的做法。@RottenCandy我想要引用。。。源\u对象应包含表\u类别包含的任何内容。。就像我会做的:source\u objects=[表\u类别]
suffixes = [BQ_TABLE_NAME_CATEGORIES, BQ_TABLE_NAME_MANUFACTURERS]
source_objects = []
for s in suffixes:
source_objects.append(globals['table_{0}'.append(s)])
...
>>> source_objects
['test.categories', 'test.manufacturers']