Data Structures

Data Structures

1. Lists

   • A list is a collection which is ordered and changeable.
   • characteristics
     • Lists need not be homogeneous always which makes it a most powerful tool in Python.
     • A single list may contain DataTypes like Integers, Strings, as well as Objects.
   • How is it made?
     • a list is created by placing all the items (elements) inside a square bracket [ ], separated by commas.

2. Series

   • Series is a one-dimensional labeled array capable of holding data of any type (integer, string, float, python objects, etc.). The axis labels are collectively called index. Series are nothing but a column in an excel sheet.
   • Creating a series
     • From lists
       • to create a series from list, we have to first create a list after that we can create a series from list.
     • From arrays
       • In order to create a series from array, we have to import a numpy module and have to use array() function.

3. Array

   • An array is a special variable, which can hold more than one value at a time.
     • You can access the values by referring to an index number.
     • An array holds elements that have the same data type.
     • Arrays can be either one dimensional or two dimensional

4. Data Frames

   • A data frame is a table or a two-dimensional array-like structure in which each column contains values of one variable and each row contains one set of values from each column.
   • Data frames can contain elements that have different data types in each row, while colums can only have the ssme data type, unlike arrays.

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