Insert the string at the beginning of all items in a list in Python

In this tutorial, we'll learn how to insert a string at the beginning of all items in a list in Python. For example, if we have a string "Tutorials_Point" and a list containing elements like "1", "2", "3", we need to add "Tutorials_Point" in front of each element to get "Tutorials_Point1", "Tutorials_Point2", "Tutorials_Point3".

Using List Comprehension with format()

The most straightforward approach is using list comprehension with string formatting ?

sample_list = [1, 2, 3]
result = ['Tutorials_Point{0}'.format(i) for i in sample_list]
print(result)

['Tutorials_Point1', 'Tutorials_Point2', 'Tutorials_Point3']

Using map() with format()

We can also use the map() function to apply string formatting to all elements ?

sample_list = [1, 2, 3]
sample_str = 'Tutorials_Point'
sample_str += '{0}'
result = list(map(sample_str.format, sample_list))
print(result)

['Tutorials_Point1', 'Tutorials_Point2', 'Tutorials_Point3']

Using f-string (Python 3.6+)

For modern Python versions, f-strings provide a cleaner syntax ?

sample_list = [1, 2, 3]
prefix = 'Tutorials_Point'
result = [f'{prefix}{i}' for i in sample_list]
print(result)

['Tutorials_Point1', 'Tutorials_Point2', 'Tutorials_Point3']

Using String Concatenation

Simple string concatenation also works effectively ?

sample_list = [1, 2, 3]
prefix = 'Tutorials_Point'
result = [prefix + str(i) for i in sample_list]
print(result)

['Tutorials_Point1', 'Tutorials_Point2', 'Tutorials_Point3']

Comparison

Conclusion

Use f-strings for modern Python applications due to their excellent readability and performance. For older Python versions, string concatenation with list comprehension provides a clean and efficient solution.