Python无法读取整个txt文件

Question

I'm learning python fundamentals and have exercise where I need to read txt file and print contents of the file line by line. Here is my code:

t = open('mbox-short.txt')

for line in t:
    print(line)

And here is the file: https://www.py4e.com/code3/mbox-short.txt

Problem is that when I run script, output doesn't show few first lines of the file. First line in mentioned above original file is:

From stephen.marquard@uct.ac.za Sat Jan  5 09:14:16 2008

and each time I run my script it shows content beginning from lines:

Received: from nakamura.uits.iupui.edu (localhost [127.0.0.1])

        by nakamura.uits.iupui.edu (8.12.11.20060308/8.12.11) with ESMTP id m04GA5LR007211

Please help me to understand what I'm doing wrong and how can I fix it. As I correctly understand, it has something to do with the txt file encoding. I've tried to download and copy it several time, changed encoding from ANSI to UTF-8 via notepad but everytime i run script it prints same output skipping few first lines and starting only from line:

Received: from nakamura.uits.iupui.edu (localhost [127.0.0.1])

Also would like to mention that I've tried to read random downloaded from the web robots.txt files and script reads everything as it should without skipping any lines. I'm using Windows 8.1 64 bit and latest Python 3.6.5. Thank you.

Answer 1

I didn't have any issue doing this :

>>> with open('./mbox-short.txt', 'r') as f:
        txt = f.read()

>>> print(txt.splitlines()[0])  # display the first line 
'From stephen.marquard@uct.ac.za Sat Jan  5 09:14:16 2008'

So I'd suggest you slightly modify your code and first read() the text file, and then use splitlines() to iterate over lines.

Answer 2

Perhaps something like this to just print the lines?

with open("./mbox-short.txt", "r") as ins:
    for line in ins:
        print(line)

Answer 3

you can open and try to find the first line using Positive Indexing using [0] if you want to find the first word use split() only , if you want to find the first line use splitlines()

f = open('mbox-short.txt', 'r').read()
print f.split()[0] # Using Positive Indexing

Output:

>>> print f.split()[0]  
From
>>>>

now we will Find the first Line

f = open('file.txt', 'r').read()
print f.splitlines()[0] # First Line Using Positive Indexing

Output:

>>> print f.splitlines()[0]
From stephen.marquard@uct.ac.za Sat Jan  5 09:14:16 2008
>>>

or you can Also Do it With readline():

f = open('mbox-short.txt', 'r').readline()
print f

Output:

>>> f = open('mbox-short.txt', 'r').readline()
>>> print f
From stephen.marquard@uct.ac.za Sat Jan  5 09:14:16 2008
>>>

Thanks!

Answer 4

@halfelf posted right answer in comments so I'll copy it here:

I guess it's just your cmd/powershell's buffer can't contain 1910 lines of that file, and the beginning lines has been scrolled

I just increased buffer size in cmd properties and now it shows all lines. Thank you all for your answers, I appreciate it.

Answer 5

for get all the lines , you must do like that:

t = open('mbox-short.txt', 'r').readlines()
for n in t:
  line = n.strip()
  print line