unique

问题 I have a dataframe where I would like to concatenate certain columns. My issue is that the text in these columns may or may not contain duplicate information. I would like to strip out the duplicates in order to retain only the relevant information. For example, if I had a data frame such as: pd.read_csv("animal.csv") animal1 animal2 label 1 cat dog dolphin 19 2 dog cat cat 72 3 pilchard 26 koala 26 4 newt bat 81 bat 81 I want to combine the columns but retain only unique information from

问题 first of all, I'm very new to Powershell, and I would like to thank all the participants of this site for helping me by providing answers across different fourms! I've accomplished a lot in a short time because of this site! Here is the issue, and I'll do my best to explain. I have a CSV file to create student accounts. Our Student management system produces a record each time a student enrolls, is altered, or exits a program. If that student "trys out" a few different programs, they will

问题 first of all, I'm very new to Powershell, and I would like to thank all the participants of this site for helping me by providing answers across different fourms! I've accomplished a lot in a short time because of this site! Here is the issue, and I'll do my best to explain. I have a CSV file to create student accounts. Our Student management system produces a record each time a student enrolls, is altered, or exits a program. If that student "trys out" a few different programs, they will

问题 I am working on a Django project where a Thing would have a unique 10 digit Key, in addition to the standard auto incrementing ID integerfield. I use a simple random number function to create it. [I'm sure there's a better way to do this too] When a Thing is created, a 10 digit Key is created. I use the .validate_unique() to check the Key's uniqueness. If its not unique, is there a simple way I can recursively call the Key generator (makeKey()) until it passes? Code follows: Models.py: class

问题 Hi I'm working on an iphone app that needs to be maintain a somewhat unique identifier per download. Is there a way to retrieve either the Apple ID used to download the App or another identifier I can use to link all devices with that download to a remote database/service? Basically I want a single instance of my custom-generated data sitting on whatever device is linked to a certain Apple ID. If iTunes signs any App that you download, using that checksum would also be an option. Any thoughts

问题 I need to efficently insert a 5 character RANDOM string into a database while also ensuring that it is UNIQUE. Generating the random string is not the problem, but currently what I am doing is generating the string and then checking the DB if it exists already... if it does, I start over. Is there a more efficient way to do this process? Please note, I do NOT want to use GUID or anything else that is more than 5 Characters.... I MUST stick to 5 Characters. PS: I don't think it makes a

问题 I have next 'member_companies' table in DB: And in model Member has a relation : public function companies() { return $this->belongsToMany(Company::class, 'member_companies'); } And it return me all companies with dublicates. For example, Member::find(238)->companies->pluck('id') return [ 6, 5, 7, 2, 10, 8, 4, 13, 14, 10, 8, 13 ] But I want only unique items. Like [ 6, 5, 7, 2, 10, 8, 4, 13, 14, ] How can I do it with eloquent relations? 回答1: You should use the unique() method in your

问题 I'm working on an interface that allows the user to select multiple "cards". Each card has a "data-name" attribute and may also have a corresponding menu item. If they select the card in the main view, it also highlights the menu item. When something is clicked, I add the "selected" class to it. I then get all the 'selected' items and count the unique data-name attributes to get the number of actual items selected. This works very well when selecting up to 5 items. For some reason, on the 6th

问题 In my application there is a need to create unique URLs (one per resource) that can be shared. Something like Google Calendar Private address for a calendar. I want to know what are the best practices for this. If it helps my application is in Django. Please let me know if this question needs more explanation. 回答1: This should be very straightforward. In your urls.py file you want a url like this: url(r'/resource/(?P<resource_name>\w+)', 'app.views.resource_func', name="priv-resource"), Then

问题 I am trying out Google App Engine Java, however the absence of a unique constraint is making things difficult. I have been through this post and this blog suggests a method to implement something similar. My background is in MySQL.Moving to datastore without a unique constraint makes me jittery because I never had to worry about duplicate values before and checking each value before inserting a new value still has room for error. "No, you still cannot specify unique during schema creation." -