Bdtjtk

Just for the record:

>>> int('55063.000000')

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

ValueError: invalid literal for int() with base 10: '55063.000000'

Got me here...

>>> float('55063.000000')

55063.0

Has to be used!

Pythonic way of iterating over a file and converting to int:

for line in open(fname):

   if line.strip():           # line contains eol character(s)

       n = int(line)          # assuming single integer on each line

What you're trying to do is slightly more complicated, but still not straight-forward:

h = open(fname)

for line in h:

    if line.strip():

        [int(next(h).strip()) for _ in range(4)]     # list of integers

This way it processes 5 lines at the time. Use h.next() instead of next(h) prior to Python 2.6.

The reason you had ValueError is because int cannot convert an empty string to the integer. In this case you'd need to either check the content of the string before conversion, or except an error:

try:

   int('')

except ValueError:

   pass      # or whatever

The following are totally acceptable in python:

• passing a string representation of an integer into int
  


• passing a string representation of a float into float
  


• passing a string representation of an integer into float
  


• passing a float into int
  


• passing an integer into float
  

But you get a ValueError if you pass a string representation of a float into int, or a string representation of anything but an integer (including empty string). If you do want to pass a string representation of a float to an int, as @katyhuff points out above, you can convert to a float first, then to an integer:

>>> int('5')

5

>>> float('5.0')

5.0

>>> float('5')

5.0

>>> int(5.0)

5

>>> float(5)

5.0

>>> int('5.0')

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

ValueError: invalid literal for int() with base 10: '5.0'

>>> int(float('5.0'))

5

Reason Is that You are getting a empty string or string as a argument into int
check it before is it empty or it contains alpha characters or not if it contains than ignore that part simply.

You've got a problem with this line:

while file_to_read != " ":

This does not find an empty string. It finds a string consisting of one space. Presumably this is not what you are looking for.

Listen to everyone else's advice. This is not very idiomatic python code, and would be much clearer if you iterate over the file directly, but I think this problem is worth noting as well.

Please test this function (split()) on a simple file. I was facing the same issue and found that it was because split() was not written properly (exception handling).

The reason you are getting this error is that you are trying to convert a space character to an integer, which is totally impossible and restricted.And that's why you are getting this error.

Check your code and correct it, it will work fine

    readings = (infile.readline())

    print readings

    while readings != 0:

        global count

        readings = int(readings)

There's a problem with that code. readings is a new line read from the file - it's a string. Therefore you should not compare it to 0. Further, you can't just convert it to an integer unless you're sure it's indeed one. For example, empty lines will produce errors here (as you've surely found out).

And why do you need the global count? That's most certainly bad design in Python.

I am creating a program that reads a
file and if the first line of the file
is not blank, it reads the next four
lines. Calculations are performed on
those lines and then the next line is
read.

Something like this should work:

for line in infile:

    next_lines = 

    if line.strip():

        for i in xrange(4):

            try:

                next_lines.append(infile.next())

            except StopIteration:

                break

    # Do your calculation with "4 lines" here

I was getting similar errors, turns out that the dataset had blank values which python could not convert to integer.

This could also happen when you have to map space separated integers to a list but you enter the integers line by line using the .input().
Like for example I was solving this problem on HackerRank Bon-Appetit, and the got the following error while compiling

So instead of giving input to the program line by line try to map the space separated integers into a list using the map() method.

I got into the same issue when trying to use readlines() inside for loop for same file object... My suspicion is firing readling() inside readline() for same file object caused this error.

Best solution can be use seek(0) to reset file pointer or
Handle condition with setting some flag then create new object for same file by checking set condition....