PPT data science python sequence numpy.pptx

PPT data science python sequence numpy.pptx

• 1.
  Python for DataScience Week 2
• 2.
  What we learntthis week ?  Sequence Data Types  Strings  Lists  Tuple  Dictionary  Sets  Numpy
• 3.
  What are SequenceData Types ?  Sequence Data Types allows us to store multiple values in an organized and efficient fashion.  String, List, Tuple are some example of Sequential types  Dictionaries and Sets are container for Non-sequential data.
• 4.
  Strings  String isan immutable sequence data type.  Immutable – which can’t be changed  It is the sequence of Unicode characters wrapped inside single, double, or triple quotes.  Example:  ‘This is a string in Python’  “This is a ‘string’ in Python”  ‘“This is a “string” in Python”’
• 5.
  Functions/Methods on String string*n - repeats the given string n times  upper() - Converts a string into upper case  lower() - Converts a string into lower case  split() - Splits the string at the specified separator, and returns a list  index() - Searches the string for a specified value and returns the position of where it is found  count() - Returns the number of times a specified value occurs in a string  capitalize() – Returns the string with its first character capitalized and the rest lowercased
• 6.
  Lists  A listis an ordered and mutable Python container.  Lists are used to store multiple items in a single variable.  Lists are created using square brackets  Example:  myList = [1 , 2 , 3 , 4 , 5]  myList = [1 , ‘two’ , 3 , ‘four’ , 5]  myList = [1 , [‘a’ , ‘b’ , ‘c’] , ‘hello’]
• 7.
  Functions/Methods on Lists append() - Adds an element at the end of the list  pop() - Removes the element at the specified position  clear() - Removes all the elements from the list  insert() - Adds an element at the specified position  reverse() - Reverses the order of the list  extend() - Add the elements of a list (or any iterable), to the end of the current list
• 8.
  Dictionary  Used tostore data values in key:value pairs.  Dictionaries are written with curly brackets, and have keys and values  Syntax:- {'key1':'value1','key2':'value2'}  Duplicates not Allowed Dictionaries cannot have two items with the same key.  Example mydictionary = { "brand": "Ford", "model": "Mustang", "year": 1964 }
• 9.
  Numpy and NumpyArray  Numpy is a Python package and it stands for numerical python.  A numpy array is a grid of values, all of the same type.  To install numpy on your system, run this command on your CMD pip install numpy  To create numpy array, we first need to import the numpy package: import numpy as np  Example:- array = np.array([1,2,3,4,5], dtype = int )
• 10.
  Methods/Functions  type(array) –this will give you the Datatype of Array  len(array) – length of array  array.ndim - return the number of dimensions of an array  array.shape - returns a tuple with each index having the number of corresponding elements  array.reshape – it changes the shape of the array
• 11.
  Thank You For yourPatience