{"id":118758,"date":"2020-10-01T06:06:52","date_gmt":"2020-10-01T06:06:52","guid":{"rendered":"https:\/\/blog.finxter.com\/?p=14044"},"modified":"2020-10-01T06:06:52","modified_gmt":"2020-10-01T06:06:52","slug":"python-reverse-list-with-slicing-an-illustrated-guide","status":"publish","type":"post","link":"https:\/\/sickgaming.net\/blog\/2020\/10\/01\/python-reverse-list-with-slicing-an-illustrated-guide\/","title":{"rendered":"Python Reverse List with Slicing \u2014 An Illustrated Guide"},"content":{"rendered":"

Summary<\/strong>: The slice notation list[::-1]<\/code> with default start<\/code> and stop<\/code> indices and negative step size -1<\/code> reverses a given list<\/code>. <\/p>\n

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\"Python<\/figure>\n<\/div>\n

Problem<\/strong>: Given a list of elements<\/a>. How to reverse the order of the elements in the list.<\/p>\n

Example<\/strong>: Say, you\u2019ve got the following list:<\/p>\n

['Alice', 'Bob', 'Carl', 'Dora']<\/pre>\n
Your goal is to reverse the elements to obtain the following result:<\/p>\n
['Dora', 'Carl', 'Bob', 'Alice']<\/pre>\n
Slicing with Default Start and Stop Values<\/h2>\n
Slicing <\/a>is a concept to carve out a substring from a given string.<\/p>\n
Use slicing notation s[start:stop:step]<\/code> to access every step<\/code>-th element starting from index start<\/code> (included) and ending in index stop<\/code> (excluded).<\/p>\n
All three arguments are optional, so you can skip them to use the default values (start=0<\/code>, stop=len(lst)<\/code>, step=1<\/code>). For example, the expression s[2:4]<\/code> from string 'hello'<\/code> carves out the slice 'll'<\/code> and the expression s[:3:2]<\/code> carves out the slice 'hl'<\/code>. Note that slicing works the same for lists and strings. <\/p>\n
You can use a negative step size (e.g., -1) to slice from the right to the left in inverse order. Here\u2019s how you can use this to reverse a list in Python:<\/p>\n
# Reverse a List with Slicing\nnames = ['Alice', 'Bob', 'Carl', 'Dora']\nnames = names[::-1]\nprint(names)\n# ['Dora', 'Carl', 'Bob', 'Alice']<\/pre>\n
Python masters know slicing from the inside out. Do you want to improve your slicing skills? Check out my book “Coffee Break Python Slicing”<\/a> that will make you a slice pro in no time! <\/p>\n
Alternatives Reversing List<\/h2>\n
Alternatively, you can also use other methods to reverse a list<\/a>.<\/p>\n