Removing blanks in Python

Question

I am new to Python so i am trying to make is simple as possible. I am working with CSV file that contains data that i have to Mapreduce. In my mapper portion I get blank data which does not let me Reduce is. This is due to CSV file has blanks in it. I need an advice on how to remove blanks in my Mapper so it will not go into my Reducer.

Example of my result.
BLUE 1
GY  1
WT  1
    1
WH  1
    1
BLACK   1
    1
GN  1
BLK 1
BLACK   1
RED 1

My code

#!/usr/bin/python

from operator import itemgetter
import sys

sys_stdin = open("Parking_Violations.csv", "r")

for line in sys_stdin:
    line = line.split(",")
    vehiclecolor = line[33]          #This is the column in CSV file where data i need is located.

    try:                                                     
        issuecolor = str(vehiclecolor)
        print("%s\t%s" % (issuecolor, 1))

     except ValueError:
        continue

Try to use [str.strip() function](https://www.tutorialspoint.com/python/string_strip.htm) let me know if this works :) — Felipe Borges, Mar 22 '20 at 20:27
I have no idea what this is supposed to do. Why `line[33]`? What's at that index? Why do you import `typing` and `itemgetter` and not use them? — roganjosh, Mar 22 '20 at 20:29
No, it doesn't, because I can't see what's at that index. You also say "blacks" instead of "blanks", multiple times. — roganjosh, Mar 22 '20 at 20:38
hint: "multiple" implies more than one. You've left another typo in. — roganjosh, Mar 22 '20 at 20:43

Johnny_xy · Accepted Answer · 2020-03-22T20:50:06.820

0

You can use the builtin string.strip function

#!/usr/bin/python

from operator import itemgetter
import sys
from typing import List, Any

sys_stdin = open("Parking_Violations.csv", "r")

for line in sys_stdin:
    vehiclecolor = line[33].strip()

    if vehiclecolor:
        issuecolor = str(vehiclecolor)
        print("%s\t%s" % (issuecolor, 1))

What it does is getting the 33rd line and strips all whitespaces from it .strip(). This assumes that your file has actually 33 lines in it otherwise it will raise an exception.

Then it checks if the vehiclecolor has any characters via the if and prints it only if there is a value.

In Python an expression of an empty string is recognized as "false".

edited Mar 22 '20 at 20:50

answered Mar 22 '20 at 20:32

Johnny_xy

376
2
8

vehiclecolor = line[33] this is the column in CSV file that has vehicle colors. – LastCossack1337 Mar 22 '20 at 20:37
In my CSV file line 33 looks like this GRY GY BLK BLK GY BK GY GY ORANG WH BK WH GR BK BK GY BLK RD ORANG GRAY WH – LastCossack1337 Mar 22 '20 at 20:44

Removing blanks in Python

1 Answers1