loop through list and list of dictionaries python

List comprehensions can also be used with conditions. This will return a list of the squares of each number in the numbers list. The list comprehension will return a list of the results of the expression for each item in the iterable.įor example, if you have a list of numbers and you want to square each number, you can use list comprehensions: numbers = The item is each element in the iterable. The expression can be anything that returns a value. List comprehensions are written as follows: It is a shorthand way to create a list without having to write a for loop. The range() function is often used in for loops to iterate through a list of values.Ī list comprehension in Python is a way to create a list from another list or iterable. If the start value is omitted, the list will start at 0. The function takes two parameters, a start value and an end value, and returns sequential numbers from the start value to the end value.įor example, if the start value is 0 and the end value is 5, the list returned would be. The range() function in Python is used to return sequential numbers. For each value, the loop prints the value multiplied by itself. In the example above, the loop variable num takes on each value in the list numbers in turn. The code block executed by the for-loop can access the current value from the sequence using the loop variable.įor example, the following for-loop iterates through a list of integers and prints the square of each integer in the list: numbers = For-loopĪ for-loop in Python iterates through a sequence of values and executes a block of code for each value in the sequence.

We’ll begin with a basic example of for loops, then move onto list comprehensions, dictionary comprehensions, and finally to generator expressions to show how each of these can help make your Python code more concise. List comprehension, dictionary comprehension, and generator expressions are three powerful examples of such expressions that are very useful. There’s no doubt that Python is a fantastic language, with powerful constructs and features to help create elegant, efficient code. However, it is possible to design even more elegant code even while using the Python programming language. Python’s use of white space makes it more readable and easier to understand. Other languages use curly braces to define code blocks, which can make the code more difficult to read. It also has a consistent indentation style. Python is said to be more readable because it uses English keywords instead of punctuation. It is often compared to other languages such as Java, C++, and Perl. Python is considered to be one of the most readable programming languages. Python has a number of advantages over other programming languages, but the hallmark advantage is its readability.

Loop through list and list of dictionaries python