Pandas data analysis tool for Python

Pandas : Python Data analysis tool.

Getting the version of Pandas

import pandas as pd 
print("Pandas Version : ",pd.__version__)

Filtering columns and create new DataFrame

my_new = my_data.filter(['equipment','category'],axis=1)

cols=['MATH','ENGLISH']
my_new=my_data[cols]

Displaying columns of the DataFrame

print(my_new.columns)

Number of rows in DataFrame.

print(len(my_new))

DataFrame	Pandas DataFrame
Settings	Managing DataFrame display option values
apply	Applying function along an Axis or elements
at	Get and Set data using rows and columns
astype	Cast to a specified dtype
cut	Using segments for categorizing values
describe	Descriptive statistics of DataFrame or series
groupby	combining data and aggregate functions
get_dummies	Convert categorical variable into dummy/indicator variables
head	First n rows of the DataFrame
isnull	Checking NaN or None data
iloc	Values at different position using integer
info	Detail information about the Dataframe
loc	Values at different position using column label
filter	Condition based filtering of rows
fillna	Filling NaN data
merge	combining DataFrame and aggregate functions
methods	Pandas DataFrame methods
nlargest	n elements in descending sorted values
mask	conditional replacement of data
query	Filtering data by using conditions
sort_values	Sort columns in ascending or descending
count	Number of rows or columns with different options
max	Max value of requried axis
mean	Mean value of requried axis
min	Min value of requried axis
std	Standard Deviation on required axis
sum	Sum of values of requried axis
set_index	Creating index using one or more columns
notnull	Not None and Not Null values checking
reset_index	Remove index of the DataFrame
value_counts	counts of unique values
unique	Unique Data of a column
where	Data updation based on condition

Creating Pandas DataFrame by using Numpy ndarray

Exercises

Exercise1	Basic data handling , DataFrame
Exercise1-1	Using cut(), groupby and plotting graphs
Exercise-Adv	Using groupby and merge of DataFrame
Exercise2	Using str.contains(), max(), min(),len() of DataFrame
Exercise3	Using date and time functions with groupby of DataFrame
Exercise3-2	Using date and time functions of DataFrame
Exercise3-3	Using date and time functions with groupby
Exercise3-4	Using date and time with where timedelta64

I/O : Input and output Data from Pandas ( Excel , MySQL , JSon)

We can’t store data in Pandas DataFrame. We can process the data by using Pandas DataFrame after reading data from different sources. Similarly after processing we can save data in different files or database by using available tools.
Data input and output from Pandas DataFrame
Filtering records

loc	Values at different position using column label
rows	Filtering rows based on data

handling string using str methods

str.contains	string matching against data columns
str.contains.sum	Max Min Sum of any column
Convert Case	Lower to Upper and vice versa
split()	Breaking string using delimiter
slice()	Substring by breaking string
cat()	Concatenate strings
count()	Number of occurences of pattern
replace()	Replace part of string by regex
len()	Length of the data in our DataFrame

Plotting Graphs using Data

Plotting graphs	Creating different type of graphs using DataFrame
Exercise	Graph using data from Excel file

Managing Date

Pandas Date and time	Managing Date and time in Pandas DataFrame

Excel to MySQL

import pandas as pd 
my_data = pd.read_excel('D:\emp.xlsx')
# reading data from root of D drive. 
from sqlalchemy import create_engine
engine = create_engine("mysql+mysqldb://userid:password@localhost/my_tutorial")

### Creating new table emp or appending existing table 
my_data.to_sql(con=engine,name='emp',if_exists='append')

MySQL to Excel

import pandas as pd 

from sqlalchemy import create_engine
engine = create_engine("mysql+mysqldb://userid:password@localhost/my_tutorial")

sql="SELECT * FROM emp "
my_data = pd.read_sql(sql,engine )

my_data.to_excel('D:\emp2.xlsx')

Columns and rows

columns	List of column headers of a DataFrame
rename	rename columns of DataFrame
add_suffix	adding suffix to column names of a DataFrame
add_prefix	adding prefix to column names of a DataFrame
drop	Delete columns or rows

Data Cleaning

Various methods in Pandas to clean data. Read from different sources then remove or fill with matching data in rows and columns

Get the list of all functions of Pandas. ( Used dir() )

import pandas as pd
print(len(dir(pd))) # 139

for i in dir(pd):
    print(i)

Pandas DataFrame

Parameters of functions

There are some common parameters used in Pandas functions. Understanding them will help in quick learning of functionality.

inplace

Boolean ( True / False ), Result is written back to same dataframe ( True ). The source dataframe is changed. False otherwise.

Numpy arrys Python & MySQL Python- Tutorials