我有一个问题：
如果我有类似
的话 ['a', 'o', 'r', 'x', ' ', 's', 'n', ' ', 'k', 'p', 'l', 'q', 't']
如何在此列表中的每个字符串之前和之后添加使用random.choice（）生成的3个字母？
答案 0 :(得分：0)
您应该执行以下操作：
Started GET "/users/edit" for ::1 at 2017-06-22 15:27:00 +0200
Processing by Users::RegistrationsController#edit as HTML
Completed 500 Internal Server Error in 2ms (ActiveRecord: 0.0ms)
NoMethodError - undefined method `validatable?' for nil:NilClass:
devise (4.3.0) app/controllers/devise_controller.rb:170:in `set_minimum_password_length'
activesupport (5.0.1) lib/active_support/callbacks.rb:382:in `block in make_lambda'
activesupport (5.0.1) lib/active_support/callbacks.rb:150:in `block (2 levels) in halting_and_conditional'
actionpack (5.0.1) lib/abstract_controller/callbacks.rb:12:in `block (2 levels) in <module:Callbacks>'
activesupport (5.0.1) lib/active_support/callbacks.rb:151:in `block in halting_and_conditional'
activesupport (5.0.1) lib/active_support/callbacks.rb:454:in `block in call'
activesupport (5.0.1) lib/active_support/callbacks.rb:454:in `call'
activesupport (5.0.1) lib/active_support/callbacks.rb:101:in `__run_callbacks__'
activesupport (5.0.1) lib/active_support/callbacks.rb:750:in `_run_process_action_callbacks'
activesupport (5.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
actionpack (5.0.1) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (5.0.1) lib/action_controller/metal/rescue.rb:20:in `process_action'
actionpack (5.0.1) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (5.0.1) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (5.0.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (5.0.1) lib/active_support/notifications.rb:164:in `instrument'
actionpack (5.0.1) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (5.0.1) lib/action_controller/metal/params_wrapper.rb:248:in `process_action'
searchkick (2.1.1) lib/searchkick/logging.rb:209:in `process_action'
activerecord (5.0.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (5.0.1) lib/abstract_controller/base.rb:126:in `process'
actionview (5.0.1) lib/action_view/rendering.rb:30:in `process'
actionpack (5.0.1) lib/action_controller/metal.rb:190:in `dispatch'
actionpack (5.0.1) lib/action_controller/metal.rb:262:in `dispatch'
actionpack (5.0.1) lib/action_dispatch/routing/route_set.rb:50:in `dispatch'
actionpack (5.0.1) lib/action_dispatch/routing/route_set.rb:32:in `serve'
actionpack (5.0.1) lib/action_dispatch/journey/router.rb:39:in `block in serve'
actionpack (5.0.1) lib/action_dispatch/journey/router.rb:26:in `serve'
actionpack (5.0.1) lib/action_dispatch/routing/route_set.rb:725:in `call'
warden (1.2.7) lib/warden/manager.rb:36:in `block in call'
warden (1.2.7) lib/warden/manager.rb:35:in `call'
rack (2.0.1) lib/rack/etag.rb:25:in `call'
rack (2.0.1) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.1) lib/rack/head.rb:12:in `call'
rack (2.0.1) lib/rack/session/abstract/id.rb:222:in `context'
rack (2.0.1) lib/rack/session/abstract/id.rb:216:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/cookies.rb:613:in `call'
activerecord (5.0.1) lib/active_record/migration.rb:553:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/callbacks.rb:38:in `block in call'
activesupport (5.0.1) lib/active_support/callbacks.rb:97:in `__run_callbacks__'
activesupport (5.0.1) lib/active_support/callbacks.rb:750:in `_run_call_callbacks'
activesupport (5.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
actionpack (5.0.1) lib/action_dispatch/middleware/callbacks.rb:36:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
better_errors (2.1.1) lib/better_errors/middleware.rb:84:in `protected_app_call'
better_errors (2.1.1) lib/better_errors/middleware.rb:79:in `better_errors_call'
better_errors (2.1.1) lib/better_errors/middleware.rb:57:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:49:in `call'
web-console (3.1.1) lib/web_console/middleware.rb:131:in `call_app'
web-console (3.1.1) lib/web_console/middleware.rb:28:in `block in call'
web-console (3.1.1) lib/web_console/middleware.rb:18:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.0.1) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.0.1) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.0.1) lib/active_support/tagged_logging.rb:69:in `block in tagged'
activesupport (5.0.1) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.0.1) lib/active_support/tagged_logging.rb:69:in `tagged'
railties (5.0.1) lib/rails/rack/logger.rb:24:in `call'
sprockets-rails (3.2.0) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/request_id.rb:24:in `call'
rack (2.0.1) lib/rack/method_override.rb:22:in `call'
rack (2.0.1) lib/rack/runtime.rb:22:in `call'
activesupport (5.0.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.1) lib/action_dispatch/middleware/static.rb:136:in `call'
rack (2.0.1) lib/rack/sendfile.rb:111:in `call'
railties (5.0.1) lib/rails/engine.rb:522:in `call'
puma (3.0.0) lib/puma/configuration.rb:221:in `call'
puma (3.0.0) lib/puma/server.rb:723:in `handle_request'
puma (3.0.0) lib/puma/server.rb:406:in `process_client'
puma (3.0.0) lib/puma/server.rb:271:in `block in run'
puma (3.0.0) lib/puma/thread_pool.rb:111:in `block in spawn_thread'
代替ranodm.sample()生成3个随机字母的列表，然后您应该random.choice() 看起来像这样：
join()我想你想在字符串的每个字母的开头和结尾都有不同的字母。如果你需要它们，你可以处理它。既然你没有提供任何例子，我回答了你的确切问题以及我对它的理解。如果您需要其他东西（看起来就像评论中的情况那样），无论如何都可以从哪里开始