Archive and Compress Files Using zip

Zip and unzip are two free command line programs that comes with Linux. For Windows, they can be downloaded from the Info-ZIP Website. This article provides the basic of archiving and compressing files using the command line zip program.

Zip one file

zip filename.zip file_to_compress

Zip multiple files

zip filename.zip file_to_compress1 file_to_compress2 file_to_compress3

Compression options

The compression level ranges from 0 to 9. Level 0 means no compression, 1 compress faster, and 9 compress better. The default is 6.

zip -9 filename.zip file_to_compress

Password protect zip archive

zip -P the_password filename.zip file_to_compress

To be prompted for password instead of specifying the password in the command line, use -e instead of -P.

zip -e filename.zip file_to_compress
Enter password:
Verify password:

Unzip files

unzip filename.zip

Unzip files with informations (verbose mode)

unzip -v filename.zip

List files that will be unzipped

unzip -l filename.zip

Test Files That Will Be Unzipped

unzip -t filename.zip

Uncompress files online

WobZIP is an online service for uncompressing compressed file online, from a url without first download the compressed file to your computer. The compressed files will be scanned using an anti-virus scanner, and any infected files will be removed. WobZip works with .rar, .7z, .tar, iso and many other compressed file types.

Link: http://www.wobzip.org

WobZIP interface

How to sort Python dictionary

To sort a Python dictionary, and append the keys into a list.

>>> x = {'a': 2, 'c': 1, 'b': 3}
>>> sorted(x, key=x.get)
['c', 'a', 'b']

To sort a Python dictionary, and append tuples of the key and value into a list.

>>> x = {'a': 2, 'c': 1, 'b': 3}
>>> [(the_key, x[the_key]) for the_key in sorted(x, key=x.get)]
[('c', 1), ('a', 2), ('b', 3)]

To sort a Python dictionary, and append the keys into a tuple, and the values into a tuple.

>>> x = {'a': 2, 'c': 1, 'b': 3}
>>> [(the_key, x[the_key]) for the_key in sorted(x, key=x.get)]
[('c', 1), ('a', 2), ('b', 3)]
>>> x = {'a': 2, 'c': 1, 'b': 3}
>>> the_keys, the_vals = zip(*[(the_key, x[the_key])
for the_key in sorted(x, key=x.get)])
>>> the_keys
('c', 'a', 'b')
>>> the_vals
(1, 2, 3)

The results from the above examples are in ascending order. To sort in descending order, attach reverse=True at the end of the sorted() function.

>>> x = {'a': 2, 'c': 1, 'b': 3}
>>> sorted(x, key=x.get, reverse=True)
['b', 'a', 'c']

Unzip a Python list

Suppose that you have a list with tuples as the member.

>>> test = [('x',1), ('y',2), ('z',3)]

We can unzip the list by using zip() in conjunction with the * operator.

>>> a, b = zip(*test)
>>> a
('x', 'y', 'z')
>>> b
(1, 2, 3)

How to convert two Python lists into a dictionary

To convert two Python lists into a dictionary. First, pair the two list with the zip() function, as key-value pairs. The last step is to use the dict() constructor to build a dictionary directly from the key-value pairs.

>>> x = ['a', 'b', 'c']
>>> y = [1 ,2 ,3]
>>> dict(zip(x,y))
{'a': 1, 'c': 3, 'b': 2}

We can also zip the two lists together, as list of tuples, and use the dict() constructor for the iterator of that list.

>>> x = ['a', 'b', 'c']
>>> y = [1, 2, 3]
>>> dict(iter(list(zip(x, y))))
{'a': 1, 'c': 3, 'b': 2}