Python dict select 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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Get value from dictionary by key with get() in Python

This article describes how to get the value from a dictionary ( dict type object) by the key in Python.

If you want to extract keys by their values, see the following article.

Get value from dictionary with dictPython dict select value ( KeyError for non-existent keys)

In Python, you can get the value from a dictionary by specifying the key like dictPython dict select value .

d = 'key1': 'val1', 'key2': 'val2', 'key3': 'val3'> print(d['key1']) # val1 

In this case, KeyError is raised if the key does not exist.

# print(d['key4']) # KeyError: 'key4' 

Specifying a non-existent key is not a problem if you want to add a new element.

For more information about adding items to the dictionary, see the following article.

Use in to check if the key exists in the dictionary.

Use dict.get() to get the default value for non-existent keys

You can use the get() method of the dictionary ( dict ) to get any default value without an error if the key does not exist.

Specify the key as the first argument. If the key exists, the corresponding value is returned; otherwise, None is returned.

d = 'key1': 'val1', 'key2': 'val2', 'key3': 'val3'> print(d.get('key1')) # val1 print(d.get('key4')) # None 

You can specify the default value to be returned when the key does not exist in the second argument.

print(d.get('key4', 'NO KEY')) # NO KEY print(d.get('key4', 100)) # 100 

The original dictionary remains unchanged.

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How To Get Dictionary Value By Key Using Python

In this tutorial, learn how to get dictionary value by key in Python. The short answer is to use the Python get() function to find the value of a known key.

The dictionary contains the keys with its associated values. The values in the dictionary variable can be identified by the key. However, if you want to know more about the dictionary, you may like to read Python Dictionary.

Get Dictionary Value By Key With Get() in Python

To get the value of the key you want, you have to use the get() function using Python. The function requires a single argument which is the key in the dictionary.

The below example contains 6 elements with both keys and the associated value of the dictionary. Use the method given below to get the value using the get() with Python.

The above example finds the value of the key “one” of Dictionary in Python. This gives value in Dictionary for the single key given. However, to get more values with the keys, you have to use the get function again.

Bonus: download a Free Python cheat sheet that will show you 20+ most important examples to learn in Python.

Find the Value Using Index Operator in Python

In addition to the above method, you can also get the values by keys in Dictionary. You have to use the Python index operator([]) to find the value of the given key.

The index operator requires a single argument to pass. You have to just pass the known key as the argument of the index operator. See the below method to get the use of index operator to get values.

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