file-iterator 1.0.1

Utilities for iterating file contents.

file-iterator

Tool to iterate the contents of different file types (plain, zip or gzip) through the same interface.

The motivation for file-iterator is accessibility to file contents and code readability, as well as providing a way to link handlers (functions) to common file-reading events (start/stop/end file reading).

Installing

file-iterator is on PyPI so all you need to do is:

pip install file-iterator

Testing

Just run:

pytest tests/

Overview - Tutorial

# Let's say we have the same text in 3 file formats.
name_txt = 'file.txt'
name_gzip = 'file.gz'
name_zip = 'file.zip'

# In Python, we could read the text file just like this:
f = open(name_txt, 'r')
for line in f:
    print(line)
f.close()

# For the GZIP file, a library is required.
import gzip
f = gzip.open(name_gzip, 'r')
for line in f:
    print(line)
f.close()

# As well as for the ZIP file.
import zipfile
z = zipfile.ZipFile(name_zip, 'r')
f = z.open(z.namelist()[0], 'r')
for line_bytes in f:
    print(line_bytes)
f.close()

With the FileIterator interface, we could iterate the contents of any file the same way. We also wouldn't need to close it.

from file_iterator import FileIterator

def print_contents(it):
    for line_bytes in it:
        print(line_bytes)
        
it = FileIterator.get_iter(name_txt, 'plain')
print_contents(it)

it = FileIterator.get_iter(name_gzip, 'gzip')
print_contents(it)

it = FileIterator.get_iter(name_zip, 'zip')
print_contents(it)

With the FileGroupIterator interface, we could iterate through all the contents simply.

from file_iterator import FileGroupIterator

names = [name_txt, name_gzip, name_zip]
it = FileGroupIterator(names)
print_contents(it)

For loops use a copy of the iterator. Therefore, the original doesn't exhaust itself and we can iterate multiple times.

print_contents(it)
print_contents(it)

We can also iterate using next().

# Returns None when everything has been read.
line_b = next(it)
while line_b:
    line_b = next(it)

# This iteration does exhaust the iterator object.
print(line_b is None) # Prints True.
for line_b in it:
    pass # Doesn't enter here.

It also supports context manager functionality:

with FileGroupIterator(names) as it:
    print_contents(it)

License

MIT

Todo

• Upload package to PyPi.
• Tests: Events.
• Tutorial: Events usage.
• Event handlers: Receive a parameter containing info about the sender (object who triggered the event).