Passing values from a csv file to python class

Question

class Devices:

    def __init__(self, fqdn):
        self.fqdn = fqdn

    def domain(self, fqdn):
        self.fqdn = fqdn.split(".")
        if fqdn.split(".")[1] == 'sa':
            return 'South America'
        elif fqdn.split(".")[1] == 'na':
            return 'North America'
        elif fqdn.split(".")[1] == 'ap':
            return 'Asia Pacific'
        elif fqdn.split(".")[1] == 'ea':
            return "Europe"


device_1 = Devices('retuyr.sa.abc.com')
device_2 = Devices('agtrah.na.abc.com')
domain1 = Devices('retuyr.sa.abc.com')
domain2 = Devices('agtrah.na.abc.com')

print('FQDN: %s' % device_1.fqdn)
print('Region is: %s' % domain1.domain(fqdn='retuyr.sa.abc.com'))
print('FQDN: %s' % device_2.fqdn)
print('Region is: %s' % domain2.domain(fqdn='agtrah.na.abc.com'))

I know there could be other ways to find the region here and it is not necessary to do a 'split'. But, I have got some other functions to run in child classes so need to keep it this way.

and the output here is:

FQDN: retuyr.sa.abc.com
Region is: South America
FQDN: agtrah.na.abc.com
Region is: North America

Now, I was able to do this much. But, what I want is to read a particular column from csv file, that has FQDN name and iterate over all the names in that file. The csv file has many columns in it and it is a very large file. How shall i parse those value inside this class. Please help!

EDIT:

My CSV looks like this:

Server, FQDN, IP_Address, Name, primary1, Address
abc1, retuyr.sa.abc.com, 10.10.10.1, someinfo, someaddress
abc1, agtrah.na.abc.com, 10.10.10.2, someinfo, someaddress
xyz2, somemorefqdns, 10.10.10.3, someinfo, someaddress
...
...

This is a pretty big csv file. but what I'm concerned here is, to only get the FQDN and get the desired region, based on my FOR loop conditions. My desired output will remain the same. Only difference is, I don't want to enter all these FQDN names manually. Just want them to read it from the csv file.

Answer 1

Using pandas as suggested in the post referenced by MooingRawr is one solution, the other is to just use the builtin csv.DictReader.

Also, it seems terribly counterproductive to initialize a class instance with one attribute value, just to overwrite it immediately with the value you actually want. I also don't believe it's good practice to drastically change what the type of that attribute is. If the initial attribute value is irrelevant, then you could keep the method as a class method instead.

Additionally, I find dictionaries for lookups to be more concise and easier to maintain than long if-statements.

import csv

DOMAINLOOKUP = {
    'sa': 'South America',
    'na': 'North America',
    'ap': 'Asia Pacific',
    'ea': "Europe",
}

class Devices():
    def __init__(self,fqdn):
        self.fqdn = fqdn

    @property
    def fqdnparts(self):
        """ Returns the fqdn split into its individual components (dot delineated) """
        ## In your original code, calling domain replaced the self.fqdn
        ## string with a list, thus making it impossible to predict the type
        ## of fqdn on any given object, so I created a new attribute to
        ## interface with the split value
        return self.fqdn.split(".")

    @property
    def domain(self):
        code = self.fqdnparts[1]
        return DOMAINLOOKUP[code]

def initializefile(file):
    with open(file) as f:
        return convertrows(csv.DictReader(f))

def convertrows(rows):
    return [Devices(row['FQDN']) for row in rows]

file = r"My\file.csv"
devices = initializefile(file)

for device in devices:
    print(f"FDQN: {device.fqdn}, Region: {device.domain}")
## Prints
## > "FDQN: retuyr.sa.abc.com, Region: South America"
## > "FDQN: agtrah.na.abc.com, Region: North America"