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+--- Thread: A strange list, how does this work? (/thread-26794.html)
A strange list, how does this work? - Pedroski55 - May-13-2020
I'm just an amateur at Python.
I'm reading a book called Python Automation Cookbook. The text contains some numbers to be replaced with X.
The book has this, which works fine:
redacted = [''.join('X' if w.isdigit() else w for w in word) for word in words]Everything seems to be backward: for loop last, if clause after the condition, yet it does exactly what it should and all the code is in list brackets []Is this some new use of a list??
RE: A strange list, how does this work? - snippsat - May-13-2020
(May-13-2020, 10:52 PM)Pedroski55 Wrote: Is this some new use of a list??It's list comprehensions not new as it has been a part Python language for 20-years PEP 202.
If break it to ordinary loop and append to a new list way,it would look look like this.
>>> words = 'hello123 world'
>>> new_lst = []
>>> for w in words:
... if w.isdigit():
... new_lst.append('X')
... else:
... new_lst.append(w)
...
>>> new_lst
['h', 'e', 'l', 'l', 'o', 'X', 'X', 'X', ' ', 'w', 'o', 'r', 'l', 'd']>>> words = 'hello123 world'
>>> [''.join('X' if w.isdigit() else w for w in word) for word in words]
['h', 'e', 'l', 'l', 'o', 'X', 'X', 'X', ' ', 'w', 'o', 'r', 'l', 'd']