python使用列表理解从CSV读取特定行

Question

Is it possible to make python read only chosen lines from a file?

Let's say I've got a CSV file, file is separated by tab and the third column is either 'a', 'b' or 'c'. I would like to have a list comprehension (or a generator, doesn't matter) which would return only those lines in the file which have chosen first column

The following throws a syntax error:

lines = [tmp = line.rstrip().split(separator_column) for line in source if tmp[2] == 'a']

Is it possible to do it in a more pythonic way than just a for-loop? So called more pythonic ways are working with the speed of C - they're faster than basic Python instructions - that's why I ask.

Answer 1

Use the csv module:

import csv
with open("your/file.csv", ...) as source:
    reader = csv.reader(source, delimiter='\t')
    selection = [row for row in reader if row[2] == 'a']