python字符串去掉空行
(How to remove whitespaces in a string in python)
- str.lstrip()
- str.rstrip()
- str.strip()
- str.replace()
- str.split()
- re.sub()
By using the above-mentioned methods, let's see how to remove whitespaces in a string.
通过使用上述方法,让我们看看如何删除字符串中的空格。
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(1. Removing leading whitespaces in a string)
1. str.lstrip()Return a copy of the string with leading whitespaces removed.
1. str.lstrip()返回删除前导空格的字符串副本。
s=" Hello Python "print (s.lstrip())#Output:Hello Python
2. re.sub()Using re.sub(), we can remove leading whitespaces.
2. re.sub()使用re.sub(),我们可以删除前导空格。
Syntax:
句法:
re.sub(pattern, repl, string, count=0, flags=0)
re. sub ( pattern , repl , string , count=0 , flags=0 )
pattern - specify the pattern to be replacedrepl - replacing the leftmost non-overlapping occurrences of pattern in string by the replacement repl. count - The optional argument count is the maximum number of pattern occurrences to be replaced. If omitted or zero, all occurrences will be replaced.
图案 -指定图案被替换REPL -由替换REPL替换模式的最左边的非重叠出现在字符串 。 count-可选参数count是要替换的最大模式出现次数。 如果省略或为零,将替换所有出现的事件。
pattern= r”^\s+”
pattern= r”^\s+”
r
Python’s raw string notation for regular expression\s
matches whitespace characters.+
It will match one or more repetitions of whitespace character.^
(Caret.) Matches the start of the string
r
Python的正则表达式\s
的原始字符串表示法与空格字符匹配。 +
它将匹配一个或多个空白字符的重复。 ^
(Caret。)匹配字符串的开头
pattern mentioned is whitespace at the beginning of the string.s1=re.sub(pattern,””,s)
提到的模式是字符串开头的空格。 s1=re.sub(pattern, ”” ,s)
re.sub() will replace the pattern (whitespaces at the beginning of string) to empty string.
re.sub()会将模式(字符串开头的空格)替换为空字符串。
s=" Hello Python "
import re
pattern= r"^\s+"s1=re.sub(pattern,"",s)
print (s1)#Output:Hello Python
(2. Removing trailing whitespace in a string)
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str.rstrip()
str.rstrip()
Return a copy of the string with trailing whitespaces removed.
返回已删除尾随空格的字符串副本。
s=" Hello Python "print (s.rstrip())#Output: Hello Python
re.sub()Using re.sub(), we can remove trailing whitespaces.
re.sub()使用re.sub(),我们可以删除结尾的空格。
pattern= r"\s+$"
r
-Python’s raw string notation for regular expression\s
— matches whitespace characters.+
It will match one or more repetitions of whitespace character.$
Matches the end of the string
r
正则表达式\s
Python原始字符串表示法-匹配空白字符。 +
它将匹配一个或多个空白字符的重复。 $
匹配字符串的结尾
pattern mentioned are whitespaces at the end of the string.s1=re.sub(pattern,””,s)
提到的模式是字符串末尾的空格。 s1=re.sub(pattern, ”” ,s)
re.sub() will replace the pattern (whitespaces at the end of the string) to empty string.
re.sub()会将模式(字符串末尾的空格)替换为空字符串。
s=" Hello Python "
import re
pattern= r"\s+$"s1=re.sub(pattern,"",s)
print (s1)#Output:Hello Python
3.删除字符串中的前导和尾随空格 (3. Removing leading and trailing whitespace in a string)
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str.strip()
str.strip()
Return the copy of the string with leading whitespaces and trailing whitespaces removed.
返回删除前导空格和尾随空格的字符串副本。
s=" Hello Python "print(s.strip())#Output:Hello Python
re.sub()
re.sub()
Using re.sub(), we can remove leading whitespaces and trailing whitespaces.pattern="^\s+|\s+$"
使用re.sub(),我们可以删除前导空格和尾随空格。 pattern= "^\s+|\s+$"
^\s+
Matches one or more whitespaces at the beginning of the string
^\s+
匹配字符串开头的一个或多个空格
\s+$
Matches one or more whitespaces at the end of the string.
\s+$
匹配字符串末尾的一个或多个空格。
|
x|y matches either x or y
|
x | y匹配x或y
s=" Hello Python "
import re
pattern="^\s+|\s+$"s1 = re.sub(pattern, "",s)
print(s1)#Output:Hello Python
(4. Remove all whitespaces in a string.)
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str.replace()Return a copy of the string with all occurrences of substring old replaced by new.
str.replace()返回该字符串的副本,其中所有出现的子字符串old都替换为new。
Syntax:
句法:
str.replace(old,new,count)
str.replace(old,new,count)
print (s.replace(" ",""))
It will replace all whitespace characters into an empty string.
它将所有空白字符替换为空字符串。
s=" Hello Python "print (s.replace(" ",""))#Output:HelloPython
re.sub()Using re.sub(), we can remove all whitespaces in the string.
re.sub()使用re.sub(),我们可以删除字符串中的所有空格。
pattern=r"\s+"s1 = re.sub(pattern, "", s)
pattern
matches all whitespaces in the string. Then re.sub(), replacing pattern(whitespaces ) to empty string.
pattern
匹配字符串中的所有空格。 然后re.sub(),将pattern(whitespaces)替换为空字符串。
s=" Hello Python "
import re
pattern=r"\s+"s1 = re.sub(pattern, "", s)
print (s1)#Output:HelloPython
str.split() Returns list of all words in the string separated using delimiter string. If the delimiter is not mentioned, by default whitespace is the delimiter.
str.split()返回使用定界符字符串分隔的字符串中所有单词的列表。 如果未提及定界符,则默认情况下空白为定界符。
join() — join () method takes all items in the iterable and combines them into a string using a separator
join() — join()方法将所有可迭代项都包含在内,并使用分隔符将它们组合成字符串
s1="".join(s.split())
Splitting the string and joining the elements using an empty string
分割字符串并使用空字符串连接元素
s=" Hello Python "print (s.split())#Output:['Hello', 'Python']
#joining the elements in the string using empty string.s1="".join(s.split())
print (s1)#Output:HelloPython
(5. Removing duplicate whitespaces in the string)
- str.split() Returns list of all words in the string separated using delimiter string. If the delimiter is not mentioned, by default whitespace is the delimiter.
str.split()返回使用定界符字符串分隔的字符串中所有单词的列表。 如果未提及定界符,则默认情况下空白为定界符。
join() — join () method takes all items in the iterable and combines them into a string using a separator
join() — join()方法将所有可迭代项都包含在内,并使用分隔符将它们组合成字符串
s1=" ".join(s.split())
Splitting the string and joining the elements using a single whitespace string
使用单个空格字符串分割字符串并连接元素
s="Hello Python"print (s.split())#Output:['Hello', 'Python']
#joining the elements in the string using single whitespace string.s1=" ".join(s.split())
print (s1)#Output:Hello Python
python字符串去掉空行