Ali obstaja funkcija Pythona, ki iz niza obreže bele prostore (presledke in tabulatorje)?
Primer: \t prime string\t
→ example string
Beli prostor na obeh straneh:
s = " \t a string example\t "
s = s.strip()
Beli prostor na desni strani:
s = s.rstrip()
Beli prostor na levi strani:
s = s.lstrip()
Kot je poudaril thedz, lahko kateri koli od teh funkcij posredujete argument za odstranitev poljubnih znakov, kot je ta:
s = s.strip(' \t\n\r')
To bo odstranilo vse znake presledka, \t
, \n
ali \r
z leve, desne ali obeh strani niza.
Zgornji primeri odstranjujejo samo nize z leve in desne strani niza. Če želite znake odstraniti tudi s sredine niza, poskusite z re.sub
:
import re
print re.sub('[\s+]', '', s)
To bi se moralo izpisati:
astringexample
Za začetni in končni beli prostor:
s = ' foo \t '
print s.strip() # prints "foo"
V nasprotnem primeru deluje regularni izraz:
import re
pat = re.compile(r'\s+')
s = ' \t foo \t bar \t '
print pat.sub('', s) # prints "foobar"
#how to trim a multi line string or a file
s=""" line one
\tline two\t
line three """
#line1 starts with a space, #2 starts and ends with a tab, #3 ends with a space.
s1=s.splitlines()
print s1
[' line one', '\tline two\t', 'line three ']
print [i.strip() for i in s1]
['line one', 'line two', 'line three']
#more details:
#we could also have used a forloop from the begining:
for line in s.splitlines():
line=line.strip()
process(line)
#we could also be reading a file line by line.. e.g. my_file=open(filename), or with open(filename) as myfile:
for line in my_file:
line=line.strip()
process(line)
#moot point: note splitlines() removed the newline characters, we can keep them by passing True:
#although split() will then remove them anyway..
s2=s.splitlines(True)
print s2
[' line one\n', '\tline two\t\n', 'line three ']