pyle 0.1

Pyle makes it easy to use Python as a replacement for command line tools such as sed or perl. For instance, to perform an in-place string substitution, overwriting the original file with the updated file, you might do:

pyle -ie "re.sub(r'alien(s|)?', r'ghost
', line)" TextAboutAliens.md

To print the first 20 characters of each line of a file:

cat README.md | pyle -e "line[:20]"

or:

pyle -e "line[:20]" README.md

In addition to line, a list called words is also available which is the current line split by whitespace. To print just the URLs in an Apache access log (the seventh “word” in the line):

tail access_log | pyle -e "words[6]"

Print the SHA 256 sum of each *.py file in the current directory:

$ ls *.py | pyle -m hashlib -e "'%s %s' % (hashlib.sha256(line).hexdigest(), line)"
348e4a65e24bab4eed8e2bbe6f4c8176ddec60051d1918eea38b34b1103a8af6 pyle.py
b28c7f73e6df990a96cfb724be1d673c2d3c43f68d4b6c06d8e5a9b29e5d12cb pyle_test.py

If your expression returns a list or a tuple, the items will be printed joined by spaces. With that in mind we can simplify the above example:

$ ls *.py | pyle -m hashlib -e "(hashlib.sha256(line).hexdigest(), line)"
348e4a65e24bab4eed8e2bbe6f4c8176ddec60051d1918eea38b34b1103a8af6 pyle.py
b28c7f73e6df990a96cfb724be1d673c2d3c43f68d4b6c06d8e5a9b29e5d12cb pyle_test.py

Print the first five lines of each file with filenames and line numbers:

$ pyle -e "'%-15s:%04d %s' % (filename, 1 + num, line) if num < 5 else None" *.py

The idea for Pyle is based on Graham Fawcett’s PyLine. Pyle is mostly compatible with PyLine but requires a -e before the evaluation statement.