Enumerable is a python library that re-implements a few core features of python's functional toolbox to be more flexible and support a more transactional way of solving problems. By design, these tools support method chaining and lazy evaluation.
Installation is simple via pip.
pip install enumerable
A common thing we do in python, especially in the IT world is for data processing. Let's say you want to load a log file and filter for specific events and strip off the line endings for further processing:
import re
from enumerable import map, filter, reduce
from operator import methodcaller
# Assume a log format along the lines of:
# CRITICAL - [5:17:2015] - <error details>
# WARNING - [2:2:2016] - <warning details>
# SUCCESS - [8:24:2017] - <success details>
with open("log.txt", 'r') as log:
def date(log_line, timestamp):
return timestamp in log_line
def critical_error(log_line):
return re.search("^CRITICAL", log_line)
# Get today's critical errors and strip
# strip the line endings
results = filter(log, date, "[3:29:2017]") \
.filter(critical_error) \
.map(methodcaller('strip'))
for line in results:
<do something>Map, Fold, and Reduce are currently provided and they are all lazy evaluated and support method chaining.
>>> import operator
>>> from enumerable import map, filter, reduce
>>>
>>> my_list = [1, 2, 3, 4, 5]
>>> # Notice that any additional arguments passed to map/filter/reduce
... # are then passed to the provided function.
... map(my_list, operator.pow, 2).to(tuple)
(1, 4, 9, 16, 25)
>>>