Reading Through: 35.2 Challenge Python For Data Science

Question

Problem:

You need to make a program to read the given number of characters of a file.
Take a number N as input and output the first N characters of the books.txt file.

My attempt is below.

I’m lost about how to get the first element from the list generated. I end up with a list of strings instead of a string of characters.

Answer 1

file = open("/usercode/files/books.txt")
n = int(input())
g=file.read()[:n]

file.close()
print(g)

I think i had the join in there unnecessarily

Answer 2

If you just want the first n characters of the file (not n characters per line of the file), then you can just use;
file.read()[:n]
This will include any invisible or whitespace characters such as '\n'

Answer 3

CarrieForle
FYI, file.read(n) will return n bytes of the file. Which in this particular case is ok (file uses default unicode type UTF-8), but could result in an issue if the unicode type in the file was larger.

Also, just to be forthcoming, I'm not sure that the way I wrote it would give a different result if the unicode type was a larger type. At least not without doing some research and testing.

Answer 4

N = int(input())
print(file.read(N))

Answer 5

file = open("/usercode/files/books.txt")
n = int(input())
for i in file.readlines():
print(''.join(i[:n]))
file.close()

Answer 6

You iterated file.readlines(). You will get the list of strings.

So don't use for loop, and use read instead.

file.read(n)

Answer 7

Thanks all

Answer 8

Fan Mason what was your final code? Whats above doesnt seen to work. Thanks!

Answer 9

Thanks Fan Mason !!

Answer 10

file = open("/usercode/files/books.txt")
#your code goes here
n = int(input())

print(file.read()[:n])
file.close()

I think this will work.)

Answer 11

My Solution:

file = open("/usercode/files/books.txt")
#your code goes here
n = int(input())
g=file.read()[:n]

file.close()
print(g)

Answer 12

N = int(input("Enter the number of characters to read: "))

with open("books.txt", "r") as file:
content = file.read(N)
print(content)

Answer 13

file = open("filename.txt",'r')
char=int(input())
a=file.read(char)
print(a)
file.close()

Answer 14

My Solution:
file = open("/usercode/files/books.txt")
#your code goes here
N = int(input())
N = file.read(N)
print(N)
file.close()

Answer 15

This is my code

file = open("/usercode/files/books.txt")

#my code
N=int(input())
print(file.read(N))
file.close()

Answer 16

Use read(N). It returns a single string with (up to) the first N characters, not a list
# input: how many characters to read
N = int(input().strip())

with open('books.txt', 'r', encoding='utf-8') as f:
chunk = f.read(N) # <- string, not list
print(chunk)

Why your code likely made a list
If you used readlines() (or iterated line-by-line), you got a list of lines. To salvage that approach:

N = int(input().strip())

with open('books.txt', 'r', encoding='utf-8') as f:
text = ''.join(f.readlines()) # merge list -> single string
print(text[:N])
But the first version (f.read(N)) is the simplest and most efficient for this task.