How to get string values from list in Python

In this Python tutorial, we will discuss different ways to get string values from a list in Python.

A Python list is a collection of items that can be of different types. On the other hand, a string is a sequence of characters. Let’s discuss how we will explore various ways to extract a string from a list in Python.

Python Extracting Individual Strings from a List

If you have a Python list and you want to extract a specific string, you can do so by referencing its index. Python’s list indices start from 0.

states = ['Florida', 'Ohio', 'Virginia', 'Michigan']
print(states[1])

In this example, we have a Python list of U.S. states and we want to extract a specific state, so we do so by referencing its index. We extract the state at index 1, which is ‘Ohio’.

Output:

Extracting Substrings from a List of Strings in Python

Suppose you have a Python list and you want to extract only the Python string. Here is how you can use list comprehension to achieve this:

cities = ['New York_8336817', 'Los Angeles_3979576', 'Chicago_2693976']
city_names = [s.split('_')[0] for s in cities]
print(city_names) 

• In this example, we use a Python list comprehension to create a new Python list, city_names, where each element is a Python substring of the corresponding element in the original Python list cities.
• The split('_')[0] operation splits each Python string at the underscore and takes the first part.

Output:

Python Searching for a String in a List

If you want to check whether a certain Python string is in a Python list, you can use the in keyword.

states = ['Texas', 'California', 'Florida', 'New York']
search = 'Florida'
if search in states:
    print(f"{search} is in the list")
else:
    print(f"{search} is not in the list")

This script prints “Florida is in the list” because ‘Florida’ does indeed exist in the list.

Output:

Using Python Map Function

The Python map function is a standard function that accepts two arguments, a function and an iterable, and returns a map object that applies the function to every item of the iterable. This can be used to extract or manipulate strings in a Python list.

populations = ['328239523', '331449281', '1459120256']
populations = list(map(int, populations)) 
print(populations)  

Here, we’ve taken a Python list of populations of U.S., India, and China (as strings), and converted them to integers using map().

Output:

Using a For Loop in Python

A for loop can be used to iterate through a Python list and perform actions on each item. This is a more manual approach compared to using methods like join() or map(), but it provides the most flexibility.

car_brands = ['Ford', 'Chevrolet', 'Dodge']
result = ''
for brand in car_brands:
    result += brand + ' '
print(result.strip()) 

This code takes each brand from the Python list and appends it to the result Python string with a space in between.

Output:

Using Python List Indexing

Python allows negative indexing, which can be used to extract strings from the end of the Python list.

states = ['California', 'Texas', 'Florida', 'New York', 'Ohio']
print(states[-1]) 

Here, we print the last state from the Python list, Ohio, using negative indexing.

Output:

Read: How to compare two lists in Python

Using the Filter Function in Python

The Python filter function constructs an iterator from elements of an iterable for which a function returns true. This is useful when you want to extract certain elements from a Python list based on some condition.

states = ['California', 'Texas', 'Florida', 'New York', 'Washington']
long_names = list(filter(lambda state: len(state) > 7, states))
print(long_names) 

In this case, we’ve filtered for states with names longer than 7 characters.

Output:

Conclusion

In summary, Python provides several methods to effectively extract strings from a list. Depending on your use case, you may use the join function, refer to a specific index, use list comprehension to extract substrings, etc.

Related Python tutorials:

• Python find index of element in list
• How to get the index of an element in Python List
• Add Elements in List in Python Using For Loop
• Python find number in String
• Strip function in Python string