Collapse a space in a string

Question

I have a line that looks something like this:

"stuff   .  // : /// more-stuff .. .. ...$%$% stuff -> DD"

and I want to disable all punctuation marks, make all uppercase letters and collapse all spaces so that they look like this:

"STUFF MORE STUFF STUFF DD"

Is this possible with one regex or do I need to combine more than two? This is what I have so far:

def normalize(string):
    import re

    string = string.upper()

    rex   = re.compile(r'\W')
    rex_s = re.compile(r'\s{2,}')

    result = rex.sub(' ', string) # this produces a string with tons of whitespace padding
    result = rex.sub('', result) # this reduces all those spaces

    return result

The only thing that doesn't work is failures. Any ideas?

Answer 1

Here's a one-step approach (but uppercase actually uses the string method - much simpler!):

rex = re.compile(r'\W+')
result = rex.sub(' ', strarg).upper()

where strargis a string argument (do not use names that have built-in shadows or standard library modules).

Answer 2

result = rex.sub(' ', string) # this produces a string with tons of whitespace padding
result = rex.sub('', result) # this reduces all those spaces

rex_s . , , - , .

result = rex.sub(' ', string) # this produces a string with tons of whitespace padding
result = rex_s.sub(' ', result) # this reduces all those spaces

Answer 3

s = "$$$aa1bb2 cc-dd ee_ff ggg."
re.sub(r'\W+', ' ', s).upper()
# ' AA1BB2 CC DD EE_FF GGG '

_ ?

re.sub(r'[_\W]+', ' ', s).upper()
# ' AA1BB2 CC DD EE FF GGG '

?

re.sub(r'[_\W]+', ' ', s).strip().upper()
# 'AA1BB2 CC DD EE FF GGG'

Answer 4

? , ?

>>> import string
>>> s = "stuff   .  // : /// more-stuff .. .. ...$%$% stuff -> DD"
>>> s2 = ''.join(c for c in s if c in string.letters + ' ')
>>> ' '.join(s2.split())
'stuff morestuff stuff DD'

Answer 5

python3, , . , , .

def collapse_whitespace_characters(raw_text):
    ret = ''
    if len(raw_text) > 1:
        prev_char = raw_text[0]
        ret += prev_char
        for cur_char in raw_text[1:]:
            if not cur_char.isspace() or cur_char != prev_char:
                ret += cur_char
            prev_char = cur_char
    else:
        ret = raw_text
    return ret

,

def collapse_whitespace(raw_text):
    ret = ''
    if len(raw_text) > 1:
        prev_char = raw_text[0]
        ret += prev_char
        for cur_char in raw_text[1:]:
            if not cur_char.isspace() or \
                    (cur_char.isspace() and not prev_char.isspace()):
                ret += cur_char
            prev_char = cur_char
    else:
        ret = raw_text
    return ret

→> collapse_whitespace_characters ('we like spaces and \ t \ t Tabs AND WHATEVER \ xa0 \ xa0IS')
'we like spaces and \ t TABS \ tAND WHATEVER \ xa0IS'

→> collapse_whitespace ('we like spaces and \ t \ t Tabs And WHATEVER \ xa0 \ xa0IS ')
' we like spaces and \ tTABS \ tAND WHATEVER \ xa0IS '

for punctuation

def collapse_punctuation(raw_text):
    ret = ''
    if len(raw_text) > 1:
        prev_char = raw_text[0]
        ret += prev_char
        for cur_char in raw_text[1:]:
            if cur_char.isalnum() or cur_char != prev_char:
                ret += cur_char
            prev_char = cur_char
    else:
        ret = raw_text
    return ret

to answer the question

orig = 'stuff   .  // : /// more-stuff .. .. ...$%$% stuff -> DD'
collapse_whitespace(''.join([(c.upper() if c.isalnum() else ' ') for c in orig]))

as said regexp will be something like

re.sub('\W+', ' ', orig).upper()