Welcome to the co u rse ! IN TR OD U C TION TO IMP OR TIN G DATA - PowerPoint PPT Presentation

Welcome to the co u rse ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON H u go Bo w ne - Anderson Data Scientist at DataCamp

Import data Flat � les , e . g . . t x ts , . cs v s Files from other so �w are INTRODUCTION TO IMPORTING DATA IN PYTHON

Import data Flat � les , e . g . . t x ts , . cs v s Files from other so �w are Relational databases INTRODUCTION TO IMPORTING DATA IN PYTHON

Plain te x t files INTRODUCTION TO IMPORTING DATA IN PYTHON

Table data 1 So u rce : Kaggle INTRODUCTION TO IMPORTING DATA IN PYTHON

Table data INTRODUCTION TO IMPORTING DATA IN PYTHON

Table data Flat � le INTRODUCTION TO IMPORTING DATA IN PYTHON

Reading a te x t file filename = 'huck_finn.txt' file = open(filename, mode='r') # 'r' is to read text = file.read() file.close() INTRODUCTION TO IMPORTING DATA IN PYTHON

Printing a te x t file print(text) YOU don't know about me without you have read a book by the name of The Adventures of Tom Sawyer; but that ain't no matter. That book was made by Mr. Mark Twain, and he told the truth, mainly. There was things which he stretched, but mainly he told the truth. That is nothing. never seen anybody but lied one time or another, without it was Aunt Polly, or the widow, or maybe Mary. Aunt Polly--Tom's Aunt Polly, she is--and Mary, and the Widow Douglas is all told about in that book, which is mostly a true book, with some stretchers, as I said before. INTRODUCTION TO IMPORTING DATA IN PYTHON

Writing to a file filename = 'huck_finn.txt' file = open(filename, mode='w') # 'w' is to write file.close() INTRODUCTION TO IMPORTING DATA IN PYTHON

Conte x t manager w ith with open('huck_finn.txt', 'r') as file: print(file.read()) YOU don't know about me without you have read a book by the name of The Adventures of Tom Sawyer; but that ain't no matter. That book was made by Mr. Mark Twain, and he told the truth, mainly. There was things which he stretched, but mainly he told the truth. That is nothing. never seen anybody but lied one time or another, without it was Aunt Polly, or the widow, or maybe Mary. Aunt Polly--Tom's Aunt Polly, she is--and Mary, and the Widow Douglas is all told about in that book, which is mostly a true book, with some stretchers, as I said before. INTRODUCTION TO IMPORTING DATA IN PYTHON

In the e x ercises , y o u’ ll : Print � les to the console Print speci � c lines Disc u ss � at � les INTRODUCTION TO IMPORTING DATA IN PYTHON

Let ' s practice ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON

The importance of flat files in data science IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON H u go Bo w ne - Anderson Data Scientist at DataCamp

Flat files INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files Te x t � les containing records That is , table data Record : ro w of � elds or a � rib u tes INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files Te x t � les containing records That is , table data Record : ro w of � elds or a � rib u tes Col u mn : feat u re or a � rib u te INTRODUCTION TO IMPORTING DATA IN PYTHON

Flat files Te x t � les containing records That is , table data Record : ro w of � elds or a � rib u tes Col u mn : feat u re or a � rib u te INTRODUCTION TO IMPORTING DATA IN PYTHON

Header INTRODUCTION TO IMPORTING DATA IN PYTHON

Header INTRODUCTION TO IMPORTING DATA IN PYTHON

File e x tension . cs v - Comma separated v al u es . t x t - Te x t � le commas , tabs - Delimiters INTRODUCTION TO IMPORTING DATA IN PYTHON

Tab - delimited file INTRODUCTION TO IMPORTING DATA IN PYTHON

Tab - delimited file INTRODUCTION TO IMPORTING DATA IN PYTHON

Ho w do y o u import flat files ? T w o main packages : N u mP y, pandas Here , y o u’ ll learn to import : Flat � les w ith n u merical data ( MNIST ) Flat � les w ith n u merical data and strings ( titanic . cs v) INTRODUCTION TO IMPORTING DATA IN PYTHON

Let ' s practice ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON

Importing flat files u sing N u mP y IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON H u go Bo w ne - Anderson Data Scientist at DataCamp

Wh y N u mP y? N u mP y arra y s : standard for storing n u merical data INTRODUCTION TO IMPORTING DATA IN PYTHON

Wh y N u mP y? N u mP y arra y s : standard for storing n u merical data Essential for other packages : e . g . scikit - learn loadt x t () genfromt x t () INTRODUCTION TO IMPORTING DATA IN PYTHON

Importing flat files u sing N u mP y import numpy as np filename = 'MNIST.txt' data = np.loadtxt(filename, delimiter=',') data [[ 0. 0. 0. 0. 0.] [ 86. 250. 254. 254. 254.] [ 0. 0. 0. 9. 254.] ..., [ 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0.]] INTRODUCTION TO IMPORTING DATA IN PYTHON

C u stomi z ing y o u r N u mP y import import numpy as np filename = 'MNIST_header.txt' data = np.loadtxt(filename, delimiter=',', skiprows=1) print(data) [[ 0. 0. 0. 0. 0.] [ 86. 250. 254. 254. 254.] [ 0. 0. 0. 9. 254.] ..., [ 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0.] [ 0. 0. 0. 0. 0.]] INTRODUCTION TO IMPORTING DATA IN PYTHON

C u stomi z ing y o u r N u mP y import import numpy as np filename = 'MNIST_header.txt' data = np.loadtxt(filename, delimiter=',', skiprows=1, usecols=[0, 2]) print(data) [[ 0. 0.] [ 86. 254.] [ 0. 0.] ..., [ 0. 0.] [ 0. 0.] [ 0. 0.]] INTRODUCTION TO IMPORTING DATA IN PYTHON

C u stomi z ing y o u r N u mP y import data = np.loadtxt(filename, delimiter=',', dtype=str) INTRODUCTION TO IMPORTING DATA IN PYTHON

Mi x ed datat y pes 1 So u rce : Kaggle INTRODUCTION TO IMPORTING DATA IN PYTHON

Mi x ed datat y pes INTRODUCTION TO IMPORTING DATA IN PYTHON

Let ' s practice ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON

Importing flat files u sing pandas IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON H u go Bo w ne - Anderson Data Scientist at DataCamp

What a data scientist needs T w o - dimensional labeled data str u ct u re ( s ) Col u mns of potentiall y di � erent t y pes Manip u late , slice , reshape , gro u pb y, join , merge Perform statistics Work w ith time series data INTRODUCTION TO IMPORTING DATA IN PYTHON

Pandas and the DataFrame INTRODUCTION TO IMPORTING DATA IN PYTHON

Pandas and the DataFrame INTRODUCTION TO IMPORTING DATA IN PYTHON

Pandas and the DataFrame DataFrame = p y thonic analog of R ’ s data frame INTRODUCTION TO IMPORTING DATA IN PYTHON

Pandas and the DataFrame INTRODUCTION TO IMPORTING DATA IN PYTHON

Manip u lating pandas DataFrames E x plorator y data anal y sis Data w rangling Data preprocessing B u ilding models Vis u ali z ation Standard and best practice to u se pandas INTRODUCTION TO IMPORTING DATA IN PYTHON

Importing u sing pandas import pandas as pd filename = 'winequality-red.csv' data = pd.read_csv(filename) data.head() volatile acidity citric acid residual sugar 0 0.70 0.00 1.9 1 0.88 0.00 2.6 2 0.76 0.04 2.3 3 0.28 0.56 1.9 4 0.70 0.00 1.9 data_array = data.values INTRODUCTION TO IMPORTING DATA IN PYTHON

Yo u’ ll e x perience : Importing � at � les in a straightfor w ard manner Importing � at � les w ith iss u es s u ch as comments and missing v al u es INTRODUCTION TO IMPORTING DATA IN PYTHON

Let ' s practice ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON

Final tho u ghts on data import IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON H u go Bo w ne - Anderson Data Scientist at DataCamp

Ne x t chapters : Import other � le t y pes : E x cel , SAS , Stata Feather Interact w ith relational databases INTRODUCTION TO IMPORTING DATA IN PYTHON

Ne x t co u rse : Scrape data from the w eb Interact w ith APIs INTRODUCTION TO IMPORTING DATA IN PYTHON

Let ' s practice ! IN TR OD U C TION TO IMP OR TIN G DATA IN P YTH ON