(i) The whitespaces can be removed, by registering new dialects using csv.register_ dialect ( ) class of csv module.
(ii) A dialect describes the format of the csv file that is to be read, In dialects the parameter "skipinitialspace" is used for removing whitespaces after the delimiter.

If an exception occurs when you are performing some operation with the file, the code exits without closing the file. The best way to do this is using the "with" statement. This ensures that the file is closed when the block inside with is exited.

Read 'r', write 'w' or append 'a'.

To sort by more than one column you can use itemgetter with multiple indices:
operator.itemgetter 
Example:
sortedlist = sorted (data, key = operator. itemgetter(1))

The row heading is get sorted, to avoid the first row should be skipped. This is can be done by using the command "next( )".

Import csv
csvData = [['Student, 'Age'], [Dhanush', '17'], ['Kalyani', '18'], ['Ram', '15']]
with open('c:\\pyprg\\ch13\\Pupil.csv', 'w') as CF:
writer = csv.writer(CF) # CF is the file object
writer.writerows(csvData) # csvData is the List name
CF.close( )

'The syntax for csv.reader() is
csv.reader(fileobject,delimiter,fmtparams)
where
(i) file object: passes the path and the mode of the file.
(ii) delimiter: an optional parameter containing the standard dilects like , | etc can be omitted
(iii) fmtparams: optional parameter which help to override the default values of the dialects like skipinitialspace, quoting etc. Can be omitted.

To create a CSV file using Microsoft Excel, launch Excel and then open the file you want to save in CSV format. For example. below is the data contained in our sample Excel worksheet:

Once the data is entered in the worksheet, select File ⟶ Save As option, and for the "Save as type option" select CSV (Comma delimited) or type the file name along with extension .csv.

Program: To read a csv file with comma (,)
#importing csv
import csv
#opening the csv file which is in different location with read mode
with open('c:\\Pyprg\ \sample1.csv', 'r') as F:
#other way to open the file is
f=('C:\\pyprg\\sample1.csv', 'r')
reader = csv.reader(F))
#printing each line of the Data row by row.
print (row)
F. close( )
Output:
['SNO','NAME', 'CITY']
['12101', 'RAM', 'CHENNAI']
['12102', 'LAVANYA' "TIRUCHY']
['12103', 'LAKSHMAN', 'MADURAI']

Program: To modify an existing file
import csv
row = ['3: 'Meena','Bangalore']
with open('Student.csv', 'r') as read file:
reader = csv.reader (read File)
lines = list (reader) 
lines [3] = row
with open ('Student.csv', 'w') as write file:
# returns the writer object which converts the user data with delimiter.
writer = csv.writer(writefile)
#writerows() method writes multiple rows to a csv file
writer. writerows(lines)
readFile.close()
writeFile.close()
Output:

We can write the csv file with quotes, by registering new dialects using csv.register_dialect() class of csv module.
Program:
import csv
info = [['SNO: 'Person: 'DOB'],
['1', 'Madhu,' '18/12/2001'],
['2', 'Sowmya', '19/2/1998'],
['3', 'Sangeetha', '20/3/1999'],
['4', 'Eshwar', '21/4/2000'],
['5', 'Anand', '22/5/2001']]
csv.register_dialect('MyDialect',quoting=csv.QUOTE_ALL)
with open('c:\\pyprg\\ch13\\person.csv', 'w') as f:
writer = csv.writer(f, dialect='myDialect')
for row in info:
writer. writerow(row)
f.close()
Output
file: "Person.csv"
"SNO","Person", "DOB", "1", "Madhu", "18/12/2001"
"2, "Sowmya", "19/2/1998", "3", "Sangeetha",
"20/3/1999", "4", "Eshwar", "21/4/2000"
"5", "Anand", "22/5/2001".