file writing not working as expected
Question: I have a python code where it will take the first column of a sample.csv file
and copy it to temp1.csv file. Now I would like to compare this csv file with
another serialNumber.txt file for any common rows. If any common rows found,
It should write to a result file. My temp1.csv is being created properly but
the problem is the result file which is being created is empty.

script.py

    
    
    import csv
    f = open("sample.csv", "r")
    reader = csv.reader(f)
    
    data = open("temp1.csv", "wb")
    w = csv.writer(data)
    for row in reader:
        my_row = []
        my_row.append(row[0])
        w.writerow(my_row)
    data.close()
    
    with open('temp1.csv', 'r') as file1:
        with open('serialNumber.txt', 'r') as file2:
            same = set(file1).intersection(file2)
            print same
    
    with open('result.csv', 'w') as file_out:
        for line in same:
            file_out.write(line)
            print line
    

sample.csv

    
    
    M11435TDS144,STB#1,Router#1 
    M11543TH4292,STB#2,Router#1 
    M11509TD9937,STB#3,Router#1
    M11543TH4258,STB#4,Router#1
    

serialNumber.txt

    
    
    G1A114042400571
    M11543TH4258
    M11251TH1230
    M11435TDS144
    M11543TH4292
    M11509TD9937
    


Answer: 
    with open('temp1.csv', 'r') as file1:
        list1 = file1.readlines()
    
    set1 = set(list1)
    
    with open('temp2.csv', 'r') as file2:
        list2 = file2.readlines()
    
    set2 = set(list2)
    

now you can process the contents as sets

I want to note that your original code does not insert line breaks after each
line so I am not sure if they would be present. If not you need to add those,
otherwise you will have a mess

