Hướng dẫn mix list python
For one-level flatten, if you care about speed, this is faster than any of the previous answers under all conditions I tried. (That is, if you need the result as a list. If you only need to iterate through it on the fly then the chain example is probably better.) It works by pre-allocating a list of the final size and copying the parts in by slice (which is a lower-level block copy than any of the iterator methods): Show
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Created: April-01, 2022
This article provides the various ways you can join a list of lists into a list in Python. Before we look at how you can join a list of lists into a list in Python, let us understand the requirement and what this joining process is called. Why We Need to Join a List of Lists Into a ListA list of lists is a 2-D format, also known as a nested list, containing several sub-lists. A list is one of the most flexible data structures in Python, so joining a list of lists into a single 1-D list can be beneficial. Here, we will convert this list of lists into a singular structure where the new list will comprise the elements contained in each sub-list from the list of lists. In the Python language, this process is also known as flattening. A 1-D list containing all elements is a better approach as:
Join a List of Lists Into a List Using the for Loop in PythonThe easiest method for converting a list of lists into a 1-D list is implementing a nested for loop with an if condition for distinct elements present. You can do this by:
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In the above code snippet, we use nested for loops. The first loop picks each element in the main list and checks if it is a list type. If the sub-element is a list, it initiates another Using the nested Join a List of Lists Into a List Using List ComprehensionAnother method of converting a nested list into a single list is using list comprehension. List comprehension provides an easily understandable single line of clean code to create entirely new lists using other structures such as strings, arrays, nested lists, etc. Let us see how you can use list comprehension to solve our problem:
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In the above code snippet, we specify the creation of a new list with elements provided by each item of each sub-list found in our original list of lists. You can also combine sub-lists containing various data types elements into your 1-D list. Join a List of Lists Into One List Using Recursion in PythonRecursion provides another way for flattening a list of lists in python. Let us see how you can implement recursion to create a single list from a list of lists:
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In the above code snippet, we have defined a recursive function named Otherwise, an if statement with an If it is true, then we return the values of the sub-list at [0] and call our function, Let us now see how to join nested lists into a list using in-built functions. Join a List of Lists Into a List Using In-Built Python FunctionsWe can use the sum() function and lambda functions to join a list of lists in Python. Join a List of Lists Using the sum() FunctionYou can use the in-built sum function to create a 1-D list from a list of lists.
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In the above program, the sum function is passed with two parameters; the first is the list of lists that it will iterate, and the second is the start of our 1-D list that is initially empty. Join a List of Lists Using Lambda FunctionYou can also use lambda, i.e., an anonymous function, to convert a list of lists into a list. Let us see with a code example:
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In the above program, we define a lambda function that iterates each
element of an item, i.e., a sub-list in the list of lists, and adds that element to the single list using Let us see how you can convert a list of lists into a 1-D list using Python libraries. One of the fastest ways that you can use to convert a 2-D list into a 1-D list in Python is by using its Functools module, which provides functions to work efficiently with higher or complex functions. We can use the
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In the above code snippet, the new 1-D list is defined with the It would be best to remember adding imports for Join a List of Lists Into a List Using the Chain() MethodAnother Python library, known as
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In the above program, the Join a List of Lists Into a List Using Numpy ModuleThe Numpy library provides the functions to concatenate the substring and flatten them into a single 1-D list. Let us take a look at how you can convert a nested list into a list using the
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In the above code snippet, we have used our list of lists, the same as the above programs, and created a new list named Related Article - Python ListHow do you join a list of lists in Python?To join a list of lists in Python:. Declare a new variable and set it to an empty list.. Use a for loop to iterate over the two-dimensional list.. Use a nested for loop to iterate over each nested list.. Append each item to the empty list.. How do I merge a list into another list in Python?In python, we can use the + operator to merge the contents of two lists into a new list. For example, We can use + operator to merge two lists i.e. It returned a new concatenated lists, which contains the contents of both list_1 and list_2. How do I put multiple lists into one list?Using + operator The + operator does a straight forward job of joining the lists together. We just apply the operator between the name of the lists and the final result is stored in the bigger list. The sequence of the elements in the lists are preserved. How do I make a list in one list in Python?There are a number of ways to flatten a list of lists in python. You can use a list comprehension, the itertools library, or simply loop through the list of lists adding each item to a separate list, etc. Let's see them in action through examples followed by a runtime assessment of each. |