Как добавить несколько значений в словарь ключа в Python?
Я хочу добавить несколько значений к определенному ключу. Как я могу это сделать?
2 ответа
Сделайте значение списка, например.
Существует несколько способов добавить значения к ключу и создать список, если он еще не существует. Я покажу один такой метод небольшими шагами.
Магия setdefault заключается в том, что она инициализирует значение для этого ключа, если этот ключ не определен, иначе он ничего не делает. Теперь, отметив, что setdefault возвращает ключ, вы можете объединить их в одну строку:
Вы должны посмотреть методы dict , в частности метод get() , и сделать некоторые эксперименты, чтобы получить удовольствие от этого.
Python dictionary multiple values
In this Python tutorial, we will study Python dictionary multiple values using some examples in python. Moreover, we will also cover these topics.
- Python dictionary multiple values for one key
- Python dictionary append multiple values
- Python dictionary multiple values for a key
- Python dictionary update multiple values
- Python dictionary with multiple values to dataframe
- Python dict remove multiple values
- Python list to dictionary multiple values
- Python sort list of dictionary by multiple values
Table of Contents
Python dictionary multiple values
- In this section, we will discuss how to create a dictionary with multiple values in Python dictionary.
- To perform this particular task ,we are going to use the dict.values() method. In Python, the dict.values() method returns all the values which are available in the dictionary and stores them into a list.
Syntax:
Let’s have a look at the syntax and understand the working of dict.values() function
Example:
Let’s take an example and check how to create a dictionary with multiple values.
In the above code, we have created a dictionary named ‘new_dictionary’ that contains elements in the form of key-value pairs. In this example, we have assigned multiple values with each key. After that, we have used the dict.values() method and it will extract only values from a given dictionary.
Here is the Screenshot of the following given code.
Python dictionary multiple values for one key
- In this Program, we will discuss how to get the multiple values for one key in Python dictionary.
- To do this task, we are going to select the specific key and it gives the value of that key.
- In this example, we will create a dictionary and then declare a variable ‘result’ in which we will assign the selected item from the dictionary.
Example:
Here is the implementation of the following given code.
As you can see in the Screenshot the output displays the multiple values of the ‘Japan’ key.
Python dictionary append multiple values
- Here we are going to discuss how to append multiple values in Python dictionary.
- By using the dictionary.update() function, we can easily append the multiple values in the existing dictionary.
- In Python, the dictionary.update() method will help the user to update the dictionary elements or if it is not present in the dictionary then it will insert the key-value pair.
Syntax:
Let’s have a look at the syntax and understand the working of the Python dictionary.update() function.
Example:
In the above code, we have appended a list of values to a key(Micheal) in the Python dictionary within the dict.update() function. Once you will execute this code the output displays the multiple values.
Here is the Output of the following given code.
Python dictionary multiple values for a key
- In this section, we will discuss how to get the multiple values for a specific key in Python dictionary.
- To do this task, we are going to use the set.default() function and it is used to set the default values to the dictionary key.
Example:
Here is the implementation of the following given code
Python dictionary update multiple values
- In this section, we will learn how to update the multiple values in Python dictionary.
- To perform this particular task, we are going to use the dictionary comprehension method this function is used to create a dictionary and it iterates the key-value pair.
- Within this dictionary comprehension method, we are going to use the assignment operator ‘+’ and this operand will help the user to add values in a given key.
Example:
In the above code, we have created a dictionary that contains elements in the form of key-value pairs. After that, to update the multiple values in the dictionary, we have assigned the ‘+2’ operator and this operand will update each value in the dictionary. Once you will execute this code the output displays the updated values in the dictionary.
Here is the execution of the following given code.
Python dictionary with multiple values to dataframe
- In this Program, we will learn how to convert a dictionary to Pandas Dataframe with multiple values in Python.
- To do this task first we will create a dictionary and assign key-value pair but multiple values will be stored in the list and it will consider as values.
- Next, to convert a dictionary into Pandas dataframe we are going to use the pd.DataFrame() syntax and within these parameters we are going to assign the dictionary ‘new_dict’ along with .T.
- In Python Pandas, the .T is used to shift columns and index in Dataframe and this ‘T’ indicates the Transpose. Next, we will use the df.reset.index() method and this method will re-order the index of the dataframe.
Syntax:
Here is the Syntax of df.reset.index() method.
Example:
Let’s take an example and check how to convert a dictionary to a dataframe with multiple values in a Python dictionary.
Source Code:
Here is the Screenshot of the following given code.
Python dict remove multiple values
- In this section, we will learn how to remove multiple values in a Python dictionary.
- To perform this particular task, we are going to use dictionary comprehension and dict.items() method for removing multiple values from a dictionary. This method will always return an object of the dictionary.
- In the dictionary comprehension method, we will set the condition new_val !=278 that indicates if the value is available in the dictionary then it will remove from the dictionary.
Example:
In the following given code, we have created a dictionary and then declared two-variable ‘rem_value’, ‘rem_value2’ and within this variable, we have used the dictionary comprehension method and it will remove multiple values from the dictionary.
Here is the implementation of the following given code.
Python list to dictionary multiple values
- In this Program, we will learn how to convert the list into the dictionary with multiple values in Python.
- To do this task, we are going to use the zip() and dict() functions. In Python the zip() function takes iterable objects as an argument like list and tuples and it always return an iterator of tuples based on the object.
- And then, to convert the object into a dictionary we are going to use the dict() function and this function is used to create a dictionary in Python.
Syntax:
Here is the Syntax of Python zip() function.
Example:
Let’s take an example and check how to convert the list into a dictionary with multiple values.
In the following given code, we have created two lists ‘list1’ and ‘list2’. In the list1 we have assigned the key elements as Country_name and list2 contains multiple values. Once you will execute this code the output displays the new dictionary that contains elements in the form of key-value pairs.
You can refer to the below Screenshot.
Python sort list of dictionary by multiple values
- In this section, we will learn how to sort a list of dictionaries by multiple values in Python.
- In this example, we will create a list of dictionaries and within this dictionary, there are the same key elements with different multiple values.
- Next, we have to sort the list of dictionaries by using the sorted() function and within this function we have specified the key element and according to the values of the key elements will be sorted in ascending order.
Example:
Here is the Screenshot of the following given code.
As you can see in the Screenshot the output displays the sorted list of dictionaries as per the condition.
Also, take a look at some more Python tutorials.
In this tutorial, we have learned Python dictionary multiple values using some examples in python. Moreover, we have also covered these topics.
- Python dictionary multiple values for one key
- Python dictionary append multiple values
- Python dictionary multiple values for a key
- Python dictionary update multiple values
- Python dictionary with multiple values to dataframe
- Python dict remove multiple values
- Python list to dictionary multiple values
- Python sort list of dictionary by multiple values
I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.
append multiple values for one key in a dictionary [duplicate]
I am new to python and I have a list of years and values for each year. What I want to do is check if the year already exists in a dictionary and if it does, append the value to that list of values for the specific key.
So for instance, I have a list of years and have one value for each year:
What I want to do is populate a dictionary with the years as keys and those single digit numbers as values. However, if I have 2009 listed twice, I want to append that second value to my list of values in that dictionary, so I want:
Right now I have the following:
7 Answers 7
If I can rephrase your question, what you want is a dictionary with the years as keys and an array for each year containing a list of values associated with that year, right? Here’s how I’d do it:
What you should end up with in years_dict is a dictionary that looks like the following:
In general, it’s poor programming practice to create «parallel arrays», where items are implicitly associated with each other by having the same index rather than being proper children of a container that encompasses them both.
You would be best off using collections.defaultdict (added in Python 2.5). This allows you to specify the default object type of a missing key (such as a list ).
So instead of creating a key if it doesn’t exist first and then appending to the value of the key, you cut out the middle-man and just directly append to non-existing keys to get the desired result.
A quick example using your data:
This way you don’t have to worry about whether you’ve seen a digit associated with a year or not. You just append and forget, knowing that a missing key will always be a list. If a key already exists, then it will just be appended to.
Python-сообщество
Добрый день!
у меня такая задача:
есть некий словарь d:=<'Спартак': 2, ‘ЦСКА’: 2, ‘Зенит’: 2>
При помощи какого оператора я могу присвоить скажем переменную неважно какую ключам или элементам словаря?
и ещё проще будет если я могу совместить два словаря, т.е. например у меня два словаря:
d:=<'Спартак': 2, ‘ЦСКА’: 2, ‘Зенит’: 2>
e:=<'Спартак': 3, ‘ЦСКА’: 5, ‘Зенит’: 1>
есть ли оператор который совмещает их чтобы получить:
f=
оператор append не работает со словарями