如何修剪字符串中的空格？

如何从Python中的字符串中删除开头和结尾的空格？

例如：

" Hello " --> "Hello"
" Hello"  --> "Hello"
"Hello "  --> "Hello"
"Bob has a cat" --> "Bob has a cat"

只是一个空格，还是所有连续的空格？如果是第二个，则字符串已经具有.strip()方法：

>>> ' Hello '.strip()
'Hello'
>>> ' Hello'.strip()
'Hello'
>>> 'Bob has a cat'.strip()
'Bob has a cat'
>>> '   Hello   '.strip()  # ALL consecutive spaces at both ends removed
'Hello'

但是，如果只需要删除一个空格，可以使用以下方法：

def strip_one_space(s):
    if s.endswith(" "): s = s[:-1]
    if s.startswith(" "): s = s[1:]
    return s

>>> strip_one_space("   Hello ")
'  Hello'

另外，请注意，str.strip()它也会删除其他空白字符（例如，制表符和换行符）。要仅删除空格，您可以指定要删除的字符作为的参数strip，即：

>>> "  Hello\n".strip(" ")
'Hello\n'

正如以上答案中指出的

myString.strip()

将删除所有前导和尾随空格字符，例如\ n，\ r，\ t，\ f，空格。

为了获得更大的灵活性，请使用以下命令

• 仅删除前导空格字符：myString.lstrip()
• 仅删除尾随空白字符：myString.rstrip()
• 删除特定的空格字符：myString.strip('\n')或myString.lstrip('\n\r')or myString.rstrip('\n\t')等等。

更多详细信息可在文档中找到

strip 不限于空白字符：

# remove all leading/trailing commas, periods and hyphens
title = title.strip(',.-')

这将删除以下所有开头和结尾的空格myString：

myString.strip()

您要strip（）：

myphrases = [ " Hello ", " Hello", "Hello ", "Bob has a cat" ]

for phrase in myphrases:
    print phrase.strip()

我想删除字符串中太多的空格（不仅在开头或结尾，而且在字符串之间）。我这样做了，因为否则我不知道该怎么做：

string = "Name : David         Account: 1234             Another thing: something  " 

ready = False
while ready == False:
    pos = string.find("  ")
    if pos != -1:
       string = string.replace("  "," ")
    else:
       ready = True
print(string)

这将在一个空间中替换双倍空格，直到您不再有双倍空格为止

我找不到想要的解决方案，所以我创建了一些自定义函数。您可以尝试一下。

def cleansed(s: str):
    """:param s: String to be cleansed"""
    assert s is not (None or "")
    # return trimmed(s.replace('"', '').replace("'", ""))
    return trimmed(s)


def trimmed(s: str):
    """:param s: String to be cleansed"""
    assert s is not (None or "")
    ss = trim_start_and_end(s).replace('  ', ' ')
    while '  ' in ss:
        ss = ss.replace('  ', ' ')
    return ss


def trim_start_and_end(s: str):
    """:param s: String to be cleansed"""
    assert s is not (None or "")
    return trim_start(trim_end(s))


def trim_start(s: str):
    """:param s: String to be cleansed"""
    assert s is not (None or "")
    chars = []
    for c in s:
        if c is not ' ' or len(chars) > 0:
            chars.append(c)
    return "".join(chars).lower()


def trim_end(s: str):
    """:param s: String to be cleansed"""
    assert s is not (None or "")
    chars = []
    for c in reversed(s):
        if c is not ' ' or len(chars) > 0:
            chars.append(c)
    return "".join(reversed(chars)).lower()


s1 = '  b Beer '
s2 = 'Beer  b    '
s3 = '      Beer  b    '
s4 = '  bread butter    Beer  b    '

cdd = trim_start(s1)
cddd = trim_end(s2)
clean1 = cleansed(s3)
clean2 = cleansed(s4)

print("\nStr: {0} Len: {1} Cleansed: {2} Len: {3}".format(s1, len(s1), cdd, len(cdd)))
print("\nStr: {0} Len: {1} Cleansed: {2} Len: {3}".format(s2, len(s2), cddd, len(cddd)))
print("\nStr: {0} Len: {1} Cleansed: {2} Len: {3}".format(s3, len(s3), clean1, len(clean1)))
print("\nStr: {0} Len: {1} Cleansed: {2} Len: {3}".format(s4, len(s4), clean2, len(clean2)))

如果要从left和right修剪指定数量的空格，可以执行以下操作：

def remove_outer_spaces(text, num_of_leading, num_of_trailing):
    text = list(text)
    for i in range(num_of_leading):
        if text[i] == " ":
            text[i] = ""
        else:
            break

    for i in range(1, num_of_trailing+1):
        if text[-i] == " ":
            text[-i] = ""
        else:
            break
    return ''.join(text)

txt1 = "   MY name is     "
print(remove_outer_spaces(txt1, 1, 1))  # result is: "  MY name is    "
print(remove_outer_spaces(txt1, 2, 3))  # result is: " MY name is  "
print(remove_outer_spaces(txt1, 6, 8))  # result is: "MY name is"

也可以使用正则表达式来完成

import re

input  = " Hello "
output = re.sub(r'^\s+|\s+$', '', input)
# output = 'Hello'

如何从Python中的字符串中删除开头和结尾的空格？

因此，下面的解决方案也将删除前导和尾随空格以及中间空格。就像您需要获取不带多个空格的清晰字符串值一样。

>>> str_1 = '     Hello World'
>>> print(' '.join(str_1.split()))
Hello World
>>>
>>>
>>> str_2 = '     Hello      World'
>>> print(' '.join(str_2.split()))
Hello World
>>>
>>>
>>> str_3 = 'Hello World     '
>>> print(' '.join(str_3.split()))
Hello World
>>>
>>>
>>> str_4 = 'Hello      World     '
>>> print(' '.join(str_4.split()))
Hello World
>>>
>>>
>>> str_5 = '     Hello World     '
>>> print(' '.join(str_5.split()))
Hello World
>>>
>>>
>>> str_6 = '     Hello      World     '
>>> print(' '.join(str_6.split()))
Hello World
>>>
>>>
>>> str_7 = 'Hello World'
>>> print(' '.join(str_7.split()))
Hello World

如您所见，这将删除字符串中的所有多个空格（输出适用Hello World于所有空格）。位置无关紧要。但是，如果您确实需要前导和尾随空格，那么strip()就会发现。