Python dictionary get one value

Python: Get first value in a dictionary

In this article we will discuss different ways to fetch the first value of a dictionary. Then we will look how to select first N values of a dictionary in python.

Table of Contents:

Get first value in a python dictionary using values() method

In python, dictionary is a kind of container that stores the items in key-value pairs. It also provides a function values() that returns an iterable sequence of all values in the dictionary. We will use that to fetch all values in the dictionary and then we will select first value from that sequence i.e.

# Dictionary of string and int word_freq = < 'Hello' : 56, "at" : 23, 'test' : 43, 'This' : 78, 'Why' : 11 ># Get first value from dictionary first_value = list(word_freq.values())[0] print('First Value: ', first_value)

Here we converted the iterable sequence of values to a list and then selected the first element from the list i.e. first value of the dictionary.

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Get first value in a dictionary using item()

item() function of dictionary returns a view of all dictionary in form a sequence of all key-value pairs. From this sequence select the first key-value pair and from that select first value.

# Dictionary of string and int word_freq = < 'Hello' : 56, "at" : 23, 'test' : 43, 'This' : 78, 'Why' : 11 ># Get first value of dictionary first_value = list(word_freq.items())[0][1] print('First Value: ', first_value)

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Get first value in a dictionary using iter() & next()

In in the above solution, we created a list of all the values and then selected the first key. It was not an efficient solution, because if our dictionary is large and we need only the first key, then why are we creating a huge list of all keys. As items() returns an iterable sequence of dictionary keys, so we can create an iterator object of this iterable sequence of key-value pairs using iter() function. Then by calling the next() function on iterator object, we can get the first element of this sequence i.e. first key-value pair of the dictionary. Then select value from the first pair. For example,

# Dictionary of string and int word_freq = < 'Hello' : 56, "at" : 23, 'test' : 43, 'This' : 78, 'Why' : 11 ># Get first value of dictionary first_value = next(iter(word_freq.items()))[1] print('First Value: ', first_value)

This is an efficient solution because didn’t iterated over all the keys in dictionary, we just selected the first one.

Get first N values from a python dictionary

Fetch all values of a dictionary as a list and then select first N entries from it. For example,

# Dictionary of string and int word_freq = < 'Hello' : 56, "at" : 23, 'test' : 43, 'This' : 78, 'Why' : 11 >n = 3 # Get first 3 values of dictionary first_n_values = list(word_freq.values())[:n] print('First 3 Values:') print(first_n_values)

We selected first three values from the dictionary.

We learned about different ways to select first value from a dictionary in python. Then we also looked at the procedure to select first N Values from a dictionary in python.

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Getting Values from a Dictionary in Python

To access all values in a dictionary in Python, call the values() method.

Or if you want to get a single value, use the square bracket [] access operator:

In case you’re unsure whether the value exists, it makes more sense to use the dict.get() method to access the values. This prevents the program from crashing if the value doesn’t exist.

This is the quick answer. But let’s take a more detailed look at accessing dictionary values in Python.

How to Get All Dictionary Values in Python

If you want to get all the values of a dictionary, use the values() method.

player_data = values = player_data.values()

This returns a dict_keys object. But you can convert it to a list using the list() function:

Now, this list contains all the values from the dictionary (the player numbers):

How to Get a Dictionary Value in Python

There are two ways to access a single value of a dictionary:

1. Get a Dictionary Value with Square Brackets

To get a single value from a dictionary, use the square brackets approach.

To do this, place the key whose value you are looking for inside square brackets after the dictionary:

player_data = ronaldo_number = player_data["Ronaldo"] print(ronaldo_number)

The problem with this approach is if there is no such key-value pair in the dictionary, an error is thrown and your program crashes.

For instance, let’s try to get a number of a player that does not exist:

player_data = rivaldo_number = player_data.get("Rivaldo") print(rivaldo_number)

To overcome this issue, use the get() method to get a value from a dictionary instead.

2. Python Dictionary get() Method

In addition to using square brackets to access dictionary values in Python, you can use the get() method.

To do this, enter the key whose value you are searching for inside the get() method.

player_data = ronaldo_number = player_data.get("Ronaldo") print(ronaldo_number)

Now if you try to access a non-existent value from the dictionary, you get a None back. This is better as your program does not crash even the value you are looking for is not there:

player_data = rivaldo_number = player_data.get("Rivaldo") print(rivaldo_number)

Conclusion

To access a dictionary value in Python you have three options:

1. Use the dictionary.values() method to get all the values
2. Use the square brackets [] to get a single value (unsafely).
3. Use the dictionary.get() method to safely get a single value from a dictionary.

Using get() is safe because it returns None if the value is not found. Using square brackets crashes your program if the value is not found.

Thanks for reading. I hope you found the values you were looking for. Happy coding!

Further Reading

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Get First Key and Value in Dictionary with Python

In Python, there are a few different ways we can get the first key/value pair of a dictionary. The easiest way is to use the items() function, convert it to a list, and access the first element.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_item = list(dictionary.items())[0] print("The first item of the dictionary has key: " + first_item[0] + " and value: " + first_item[1]) #Output: The first item of the dictionary has key: key1 and value: This

Another way to get the first key and value in a dictionary is to convert it to a list and access the first element. This will get the first key, and then you can get the first value by accessing that key in the

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_key = list(dictionary)[0] print("The first key of the dictionary is: " + first_key) #Output: The first key of the dictionary is: key1

If you only care about getting the first value of a dictionary, you can use the dictionary values() function.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_value = list(dictionary.values())[0] print("The first value of the dictionary is: " + first_value) #Output: The first value of the dictionary is: This

In Python, dictionaries are a collection of key/value pairs separated by commas. When working with dictionaries, it can be useful to be able to easily access certain elements.

We can easily get the first item from a dictionary and get the first key and first value.

The easiest way to get the first item from a dictionary is with the items() function. The items() function returns a dict_items object, but we can convert it to a list to easily and then access the first element like we would get the first item in a list.

Below is an example of how you can use the dictionary items() function to get the first item of a dictionary.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_item = list(dictionary.items())[0] print(first_item) print("The first item of the dictionary has key: " + first_item[0] + " and value: " + first_item[1]) #Output: ('key1','This') The first item of the dictionary has key: key1 and value: This

Get First Key in Dictionary Using Python

The example above is great for getting the first item in a dictionary. If you only care about getting the first key, there are a few ways you can get the first key of a dictionary.

You can use the Python dictionary keys() function, convert it to a list, and access the first element, or just convert the dictionary to a list and then access the first element.

Below shows two different ways to get the first key from a dictionary in Python.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_key = list(dictionary)[0] print("The first key of the dictionary is: " + first_key) first_key = list(dictionary.keys())[0] print("The first key of the dictionary is: " + first_key) #Output: The first key of the dictionary is: key1 The first key of the dictionary is: key1

Get First Value in Dictionary Using Python

If you only care about getting the first value, there are a few ways you can get the first value of a dictionary.

To get the first value in a dictionary, you can use the Python dictionary values() function, convert it to a list, and access the first element.

Below shows two different ways to get the first value from a dictionary in Python.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >first_value = list(dictionary.values())[0] print("The first value of the dictionary is: " + first_value) #Output: The first value of the dictionary is: This

Get the First n Items in Dictionary Using Python

We can use the items() function to get the first n items in a dictionary using Python. Since we convert the dict_items object to a list, we can use slicing just like with lists to get the first n key/value pairs in a dictionary.

Below is an example of how you can use Python to get the first 3 items in a dictionary.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >dict_items_list = list(dictionary.items())[0:3] for x in dict_items_list: print(x) #Output: ('key1', 'This') ('key2', 'is') ('key3', 'a')

Get the Last Item in Dictionary Using Python

Finally, if you want to get the last item in a dictionary, or get the last key and last value, you can use a very similar method as described above.

Now, instead of getting the first element, we get the last item from the list.

Below is an example in Python of how to get the last key and last value in a dictionary.

dictionary = < "key1":"This", "key2":"is", "key3":"a", "key4":"dictionary." >last_item = list(dictionary.items())[-1] print("The first item of the dictionary has key: " + last_item[0] + " and value: " + last_item[1]) #Output: The first item of the dictionary has key: key4 and value: dictionary.

Hopefully this article has been useful for you to understand how to get the first item from a dictionary in Python.

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