13 data.frame & DataFrame

• Set the current working directory to read the data file
• Check all objects in the current working directory
• R base format of data is data.frame
• In Python, we need to load pandas library

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13.1 R

• The R object of representing data in rows and columns is data.frame

• The data.frame object is included with base R

• This section sets the working directory where a csv file is located and read the data from the location in R environment

Function	Explanation	Example
setwd	Set the working directory	setwd(Path/to/folder)
getwd	Get the current working directory	getwd()
dir	List files in a directory	dir()
ls	List all objects loaded in the global environment	ls()
rm	Remove an object from the global environment	rm(obj_name)
read.table	Read a tabular data - it reads tabular data with field names and specific delimiter	read.table(Path/to/folder/file_name.txt)
read.csv	Read a CSV file	read.csv(Path/to/folder/file_name.csv)

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13.2 Python

• We need to load pandas library which will allow access Python object DataFrame

• pandas is a flexible and easy data analysis and manipulation tool in Python

• This section sets the working directory where a csv file is located and read the data from the location in Python environment

• Check (pandas website)[https://pandas.pydata.org/] for further details

import os

import pandas as pd

Function	Explanation	Example
chwd	Function from the os library to set (check) into the working directory	os.chdir('Path/to/folder')
getcwd	Function from the os library to get the current working directory	os.getcwd()
listdir	List files in a directory	os.listdir()
globals	List all objects loaded in the global environment	globals()
del	Remove an object from the global environment	del(obj_name)
read_csv	Function from the pandas library to read tabular data with delimiter	pd.read_csv('Path/to/folder/file_name.txt', delimiter = '\t')
read_csv	Function from the pandas library to read CSV data	pd.read_csv('Path/to/folder/file_name.csv')

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