How to read desired rows from large CSV files in python - python-3.x

Question

I am trying to search for data from a CSV file and pass on the data to another python code.
The CSV file has 100000+ rows and from them, I want to pass on the requested data per my choice.
Actual Code:
input_file = 'trusted.csv'
users = []
with open(input_file, encoding='UTF-8') as f:
rows = csv.reader(f,delimiter=",",lineterminator="\n")
next(rows, None)
for row in rows:
user = {}
user['username'] = row[0]
user['id'] = int(row[1])
user['access_hash'] = int(row[2])
user['name'] = row[3]
users.append(user)
Parsing data to code:
g_index = input("Enter a Number: ")
target_group=groups[int(g_index)]
target_group.access_hash
The Actual code will parse All the rows from the CSV file and I am trying to find a solution for a python code that can pass on data - like from 11 to 20 rows, 50 to 100 rows likewise.
I tried the below code but received an error when the data was parsed to another python code:
import CSV
input_file = 'lucky280.csv'
start = 10
stop = start + 10
users = []
with open(input_file, encoding='UTF-8') as f:
rows = csv.reader(f,delimiter=",",lineterminator="\n")
for i, line in enumerate(rows):
if i >= start:
users.append(line)
if i > stop:
break
for row in rows:
user = {}
user['username'] = row[0]
user['id'] = int(row[1])
user['access_hash'] = int(row[2])
user['name'] = row[3]
users.append(user)
ERROR :
Traceback (most recent call last):
File "", line 10, in
print ("Adding {}".format(user['id']))
TypeError: list indices must be integers or slices, not str
If I use the Actual code the file reading will work fine but it will parse all the data in the file.
Please HELP!
After recommendation I also tried
input_file = 'lucky280.csv'
users = []
from itertools import islice
with open(input_file, encoding='UTF-8') as f:
rows = csv.reader(f,delimiter=",",lineterminator="\n")
rowiter = islice(rows, 3, 5)
for item in rowiter:
for row in rows:
user = {}
user['username'] = row[0]
user['id'] = int(row[1])
user['access_hash'] = int(row[2])
user['name'] = row[3]
users.append(user)
got the below error
IndexError Traceback (most recent call last)
<ipython-input-108-9f4099c2e53d> in <module>()
10 user = {}
11 user['username'] = row[0]
---> 12 user['id'] = int(row[1])
13 user['access_hash'] = int(row[2])
14 user['name'] = row[3]
IndexError: list index out of range

Answer 1

You can use islice from itertools
So here i have as sample csv file
X Y
0 21 test3
1 8 test1
2 75 test1
3 26 test2
4 98 test3
5 63 test3
6 65 test3
7 39 test3
8 74 test1
9 26 test2
And suppose I want only rows 3 and 4
>>> from itertools import islice
>>> with open('test.csv') as f:
... rows = csv.reader(f)
... rowiter = islice(rows, 3, 5)
... for item in rowiter:
... print(item)
gives me the following output
['2', '75', 'test1']
['3', '26', 'test2']
Update
input_file = 'trusted.csv'
start = 10
stop = start + 10
users = []
with open(input_file, encoding='UTF-8') as f:
rows = csv.reader(f,delimiter=",",lineterminator="\n")
rowiter = islice(rows, start, stop)
for row in rowiter :
user = {}
user['username'] = row[0]
user['id'] = int(row[1])
user['access_hash'] = int(row[2])
user['name'] = row[3]
users.append(user)