What is internally happening which does not let me print output ? last line of csv file-CodePudding

I am trying to fetch last record of csv file using below code.

Nothing gets printed as an output.

I have 101 records in csv file. Need to fetch last record of file

Code :

import csv

count = 0
with open('/folder/emp.csv','r') as csvdt:

  csv_rd = csv.reader(csvdt)
  get_record_count  = len(list(csv_rd)) #101

  for j in  csv_rd:
    if count == get_record_count:
      print(j)
    else:
      count = count   1

What is internally happening which does not let me print output ?

CodePudding user response：

csv_rd is a generator, so you exhaust the content of csv_rd if you apply len(list(csv_rd)). In order to prevent exhaustion, you have to get the list of csv_rd first.

Code:

import csv

with open('/folder/emp.csv','r') as csvdt:

    csv_rd = csv.reader(csvdt)

    lines = list(csv_rd)
    get_record_count = len(lines) #101

    for i, line in enumerate(lines, 1):
        if i == get_record_count:
            print(line)

If what you want to do is only getting the last line, the following code might be usefull as well.

import csv

with open('/folder/emp.csv','r') as csvdt:
    csv_rd = csv.reader(csvdt)
    last_line = list(csv_rd)[-1]
    print(last_line)