I need to write a program in a functional way. I have a text and I need to calculate a number of unique words, (for example: "word word, word word?" - has 3 different words, punctuation matters.
I have a code:
import sys
import re
print(len(set(re.findall('[^ \n]+', sys.stdin.readline()))))
the problem is that i can read only one line this way, I tried to replace readline by read, but it not working.
Python file objects are iterable. So we can apply the usual itertools mix to them. What you've done with one line can be easily extended to several.
print(list(map(lambda x: len(set(re.findall('[^ \n]+', x))), sys.stdin)))
As was mentioned in the other answer, I suggest using some intermediate variables to make this prettier (doing so does not affect how functional your code is, provided you never mutate the variables)
def handle_line(x):
coll = set(re.findall('[^ \n]+', x))
return len(coll)
result = map(handle_line, sys.stdin)
print(list(result))
If you want to run once for the whole file, rather than running a separate iteration on each line, you can get the whole file like so.
# Be careful; this will DEFINITELY fail on large files
file_data = '\n'.join(list(sys.stdin))
Then you can run your len(set(...)) sequence of operations on the resulting string instead.
What about simply
text = "word word, word word?"
words = text.split()
unique_words = set(words)
nr_unique_words = len(unique_words)
Of course, this can be written mure succinctly:
print(len(set("word word, word word?".split())))
