将CamelCase转换为snake_case的优雅Python函数?
例如:将CamelCase转换为snake_case的优雅Python函数?,python,camelcasing,Python,Camelcasing,例如: >>> convert('CamelCase') 'camel_case' camelcase_to_underscore('ThisUser') 不在标准库中,但我发现它似乎包含了您需要的功能。为了好玩: >>> def un_camel(input): ... output = [input[0].lower()] ... for c in input[1:]: ... if c in ('ABCDEFG
>>> convert('CamelCase')
'camel_case'
camelcase_to_underscore('ThisUser')
不在标准库中,但我发现它似乎包含了您需要的功能。为了好玩:
>>> def un_camel(input):
... output = [input[0].lower()]
... for c in input[1:]:
... if c in ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'):
... output.append('_')
... output.append(c.lower())
... else:
... output.append(c)
... return str.join('', output)
...
>>> un_camel("camel_case")
'camel_case'
>>> un_camel("CamelCase")
'camel_case'
或者,更有趣的是:
>>> un_camel = lambda i: i[0].lower() + str.join('', ("_" + c.lower() if c in "ABCDEFGHIJKLMNOPQRSTUVWXYZ" else c for c in i[1:]))
>>> un_camel("camel_case")
'camel_case'
>>> un_camel("CamelCase")
'camel_case'
一个使用正则表达式的可怕示例(您可以很容易地清理它:): 但是对getHTTPResponseCode有效 或者,使用lambda:
p = re.compile("([A-Z]+[a-z]+)([A-Z]?)")
print p.sub(lambda x: x.group(1).lower() + "_" + x.group(2).lower(), "CamelCase")
print p.sub(lambda x: x.group(1).lower() + "_" + x.group(2).lower(), "getHTTPResponseCode")
编辑:对于“Test”这样的情况,应该很容易看出还有改进的余地,因为下划线是无条件插入的。以下是我的解决方案:
def un_camel(text):
""" Converts a CamelCase name into an under_score name.
>>> un_camel('CamelCase')
'camel_case'
>>> un_camel('getHTTPResponseCode')
'get_http_response_code'
"""
result = []
pos = 0
while pos < len(text):
if text[pos].isupper():
if pos-1 > 0 and text[pos-1].islower() or pos-1 > 0 and \
pos+1 < len(text) and text[pos+1].islower():
result.append("_%s" % text[pos].lower())
else:
result.append(text[pos].lower())
else:
result.append(text[pos])
pos += 1
return "".join(result)
def un_camel(文本):
“”“将CamelCase名称转换为分数不足的名称。
>>>un_camel(“CamelCase”)
“骆驼案”
>>>un_camel('getHTTPResponseCode'))
'获取\u http\u响应\u代码'
"""
结果=[]
pos=0
而pos0且文本[pos-1].islower()或pos-1>0且\
pos+1
它支持评论中讨论的那些角落案例。例如,它将getHTTPResponseCode
转换为get\u http\u response\u code
。Camel case转换为snake case
重新导入
名称='CamelCaseName'
name=re.sub(r’(?哇,我刚从django snippets.ref偷了这个
相当优雅
camelcase_to_underscore = lambda str: re.sub(r'(?<=[a-z])[A-Z]|[A-Z](?=[^A-Z])', r'_\g<0>', str).lower().strip('_')
返回:
'this_user'
非常好的正则表达式建议在:
(?
如果python有一个字符串拆分方法,它应该可以工作
在Java中:
String s=“loremIpsum”;
单词=s.split((?<;!^)(?=[A-Z]);
以下是我为更改制表符分隔文件的标题所做的一些操作。我省略了仅编辑文件第一行的部分。通过重新库,您可以非常轻松地使其适应Python。这还包括分隔数字(但将数字保持在一起).我分两步做,因为这比告诉它不要在行或制表符的开头加下划线更容易
第一步…查找大写字母或小写字母前面的整数,并在它们前面加下划线:
搜索:
([a-z]+)([A-Z]|[0-9]+)
([A-Z])
替换:
\1_\l\2/
第二步…执行上述步骤,然后再次运行该步骤,将所有大写字母转换为小写字母:
搜索:
([a-z]+)([A-Z]|[0-9]+)
([A-Z])
替换(即反斜杠,小写L,反斜杠,一):
这一次我运气不错:
import re
def camelcase_to_underscore(s):
return re.sub(r'(^|[a-z])([A-Z])',
lambda m: '_'.join([i.lower() for i in m.groups() if i]),
s)
如果你想的话,这显然可以优化一点速度
import re
CC2US_RE = re.compile(r'(^|[a-z])([A-Z])')
def _replace(match):
return '_'.join([i.lower() for i in match.groups() if i])
def camelcase_to_underscores(s):
return CC2US_RE.sub(_replace, s)
我不知道为什么这些都这么复杂
在大多数情况下,简单的表达式([A-Z]+)
会起作用
>>> re.sub('([A-Z]+)', r'_\1','CamelCase').lower()
'_camel_case'
>>> re.sub('([A-Z]+)', r'_\1','camelCase').lower()
'camel_case'
>>> re.sub('([A-Z]+)', r'_\1','camel2Case2').lower()
'camel2_case2'
>>> re.sub('([A-Z]+)', r'_\1','camelCamelCase').lower()
'camel_camel_case'
>>> re.sub('([A-Z]+)', r'_\1','getHTTPResponseCode').lower()
'get_httpresponse_code'
要忽略第一个字符,只需添加look-behind(?!^)
如果您想将ALLCaps分隔为ALLCaps,并希望字符串中包含数字,您仍然不需要执行两次单独的运行,只需使用
这个表达式(?>>a=re.compile(')((?我不知道为什么同时使用这两个.sub()调用?:)我不是正则表达式大师,但我将函数简化为这个函数,这适合我的特定需求,我只需要一个解决方案,将CAMELCASEDVAR从POST请求转换为带有下划线的vars_:
def myFunc(...):
return re.sub('(.)([A-Z]{1})', r'\1_\2', "iTriedToWriteNicely").lower()
它不适用于像getHTTPResponse这样的名称,因为我听说它的命名约定不好(应该像getHTTPResponse,很明显,它更容易记住这个表单)。我正在寻找解决同样问题的方法,只是我需要一个链;例如
"CamelCamelCamelCase" -> "Camel-camel-camel-case"
从这里两个字的解决方案开始,我想到了以下几点:
"-".join(x.group(1).lower() if x.group(2) is None else x.group(1) \
for x in re.finditer("((^.[^A-Z]+)|([A-Z][^A-Z]+))", "stringToSplit"))
大多数复杂的逻辑都是为了避免第一个单词的小写。如果您不介意修改第一个单词,这里有一个更简单的版本:
"-".join(x.group(1).lower() for x in re.finditer("(^[^A-Z]+|[A-Z][^A-Z]+)", "stringToSplit"))
当然,您可以预编译正则表达式或使用下划线而不是连字符进行连接,如其他解决方案中所述。这不是一种优雅的方法,是简单状态机(位域状态机)的“低级”实现,可能是解决这个问题的最反pythonic的模式,但是re模块也实现了一个太复杂的状态机来解决这个简单的任务,所以我认为这是一个很好的解决方案
def splitSymbol(s):
si, ci, state = 0, 0, 0 # start_index, current_index
'''
state bits:
0: no yields
1: lower yields
2: lower yields - 1
4: upper yields
8: digit yields
16: other yields
32 : upper sequence mark
'''
for c in s:
if c.islower():
if state & 1:
yield s[si:ci]
si = ci
elif state & 2:
yield s[si:ci - 1]
si = ci - 1
state = 4 | 8 | 16
ci += 1
elif c.isupper():
if state & 4:
yield s[si:ci]
si = ci
if state & 32:
state = 2 | 8 | 16 | 32
else:
state = 8 | 16 | 32
ci += 1
elif c.isdigit():
if state & 8:
yield s[si:ci]
si = ci
state = 1 | 4 | 16
ci += 1
else:
if state & 16:
yield s[si:ci]
state = 0
ci += 1 # eat ci
si = ci
print(' : ', c, bin(state))
if state:
yield s[si:ci]
def camelcaseToUnderscore(s):
return '_'.join(splitSymbol(s))
splitsymbol可以解析所有大小写类型:UpperSequenceInterleave、under_score、BIG_符号和cammelCasedMethods
我希望它是有用的包内索引可以为您处理这些事情。在这种情况下,您将寻找:
就我个人而言,我不确定在python中使用正则表达式的任何东西怎么能被描述为优雅的。这里的大多数答案只是做“代码高尔夫”类型的重新设计。优雅的编码应该很容易理解
def to_snake_case(not_snake_case):
final = ''
for i in xrange(len(not_snake_case)):
item = not_snake_case[i]
if i < len(not_snake_case) - 1:
next_char_will_be_underscored = (
not_snake_case[i+1] == "_" or
not_snake_case[i+1] == " " or
not_snake_case[i+1].isupper()
)
if (item == " " or item == "_") and next_char_will_be_underscored:
continue
elif (item == " " or item == "_"):
final += "_"
elif item.isupper():
final += "_"+item.lower()
else:
final += item
if final[0] == "_":
final = final[1:]
return final
>>> to_snake_case("RegularExpressionsAreFunky")
'regular_expressions_are_funky'
>>> to_snake_case("RegularExpressionsAre Funky")
'regular_expressions_are_funky'
>>> to_snake_case("RegularExpressionsAre_Funky")
'regular_expressions_are_funky'
def to_snake_案例(非_snake_案例):
最终=“”
对于x范围内的i(len(不是蛇的情况)):
项目=非蛇型案例[i]
如果i>>以“蛇”为例(“常规表达是时髦的”)
“正则表达式很时髦”
>>>以蛇为例(“常规表达很时髦”)
“正则表达式很时髦”
>>>对蛇的案例(“常规表达是时髦的”)
“正则表达式很时髦”
简洁,不含正则表达式,但HTTPResponseCode=>HttpResponseU代码:
def from_camel(name):
"""
ThisIsCamelCase ==> this_is_camel_case
"""
name = name.replace("_", "")
_cas = lambda _x : [_i.isupper() for _i in _x]
seq = zip(_cas(name[1:-1]), _cas(name[2:]))
ss = [_x + 1 for _x, (_i, _j) in enumerate(seq) if (_i, _j) == (False, True)]
return "".join([ch + "_" if _x in ss else ch for _x, ch in numerate(name.lower())])
使用正则表达式可能是最短的,但此解决方案更具可读性:
def to_snake_case(s):
snake = "".join(["_"+c.lower() if c.isupper() else c for c in s])
return snake[1:] if snake.startswith("_") else snake
使用:str.capitalize()
转换第一个le
def splitSymbol(s):
si, ci, state = 0, 0, 0 # start_index, current_index
'''
state bits:
0: no yields
1: lower yields
2: lower yields - 1
4: upper yields
8: digit yields
16: other yields
32 : upper sequence mark
'''
for c in s:
if c.islower():
if state & 1:
yield s[si:ci]
si = ci
elif state & 2:
yield s[si:ci - 1]
si = ci - 1
state = 4 | 8 | 16
ci += 1
elif c.isupper():
if state & 4:
yield s[si:ci]
si = ci
if state & 32:
state = 2 | 8 | 16 | 32
else:
state = 8 | 16 | 32
ci += 1
elif c.isdigit():
if state & 8:
yield s[si:ci]
si = ci
state = 1 | 4 | 16
ci += 1
else:
if state & 16:
yield s[si:ci]
state = 0
ci += 1 # eat ci
si = ci
print(' : ', c, bin(state))
if state:
yield s[si:ci]
def camelcaseToUnderscore(s):
return '_'.join(splitSymbol(s))
>>> inflection.underscore('CamelCase')
'camel_case'
def to_snake_case(not_snake_case):
final = ''
for i in xrange(len(not_snake_case)):
item = not_snake_case[i]
if i < len(not_snake_case) - 1:
next_char_will_be_underscored = (
not_snake_case[i+1] == "_" or
not_snake_case[i+1] == " " or
not_snake_case[i+1].isupper()
)
if (item == " " or item == "_") and next_char_will_be_underscored:
continue
elif (item == " " or item == "_"):
final += "_"
elif item.isupper():
final += "_"+item.lower()
else:
final += item
if final[0] == "_":
final = final[1:]
return final
>>> to_snake_case("RegularExpressionsAreFunky")
'regular_expressions_are_funky'
>>> to_snake_case("RegularExpressionsAre Funky")
'regular_expressions_are_funky'
>>> to_snake_case("RegularExpressionsAre_Funky")
'regular_expressions_are_funky'
def from_camel(name):
"""
ThisIsCamelCase ==> this_is_camel_case
"""
name = name.replace("_", "")
_cas = lambda _x : [_i.isupper() for _i in _x]
seq = zip(_cas(name[1:-1]), _cas(name[2:]))
ss = [_x + 1 for _x, (_i, _j) in enumerate(seq) if (_i, _j) == (False, True)]
return "".join([ch + "_" if _x in ss else ch for _x, ch in numerate(name.lower())])
def to_snake_case(s):
snake = "".join(["_"+c.lower() if c.isupper() else c for c in s])
return snake[1:] if snake.startswith("_") else snake
def camelify(out):
return (''.join(["_"+x.lower() if i<len(out)-1 and x.isupper() and out[i+1].islower()
else x.lower()+"_" if i<len(out)-1 and x.islower() and out[i+1].isupper()
else x.lower() for i,x in enumerate(list(out))])).lstrip('_').replace('__','_')
CamelCamelCamelCase -> camel_camel_camel_case
HTTPRequest -> http_request
GetHTTPRequest -> get_http_request
getHTTPRequest -> get_http_request
import re
def convert(name):
return re.sub(r'([A-Z]*)([A-Z][a-z]+)', lambda x: (x.group(1) + '_' if x.group(1) else '') + x.group(2) + '_', name).rstrip('_').lower()
def uncamelize(s):
buff, l = '', []
for ltr in s:
if ltr.isupper():
if buff:
l.append(buff)
buff = ''
buff += ltr
l.append(buff)
return '_'.join(l).lower()
class MapPrice(Model):
price_before_vat = DecimalType(serialized_name='priceBeforeVat')
vat_rate = DecimalType(serialized_name='vatRate')
vat = DecimalType()
total_price = DecimalType(serialized_name='totalPrice')
>>> from stringcase import pascalcase, snakecase
>>> snakecase('FooBarBaz')
'foo_bar_baz'
>>> pascalcase('foo_bar_baz')
'FooBarBaz'
def convert(name):
return reduce(
lambda x, y: x + ('_' if y.isupper() else '') + y,
name
).lower()
def convert(name):
return reduce(
lambda x, y: x + ('_' if y.isupper() and not x.endswith('_') else '') + y,
name
).lower()
import re
def convert (camel_input):
words = re.findall(r'[A-Z]?[a-z]+|[A-Z]{2,}(?=[A-Z][a-z]|\d|\W|$)|\d+', camel_input)
return '_'.join(map(str.lower, words))
# Let's test it
test_strings = [
'CamelCase',
'camelCamelCase',
'Camel2Camel2Case',
'getHTTPResponseCode',
'get200HTTPResponseCode',
'getHTTP200ResponseCode',
'HTTPResponseCode',
'ResponseHTTP',
'ResponseHTTP2',
'Fun?!awesome',
'Fun?!Awesome',
'10CoolDudes',
'20coolDudes'
]
for test_string in test_strings:
print(convert(test_string))
camel_case
camel_camel_case
camel_2_camel_2_case
get_http_response_code
get_200_http_response_code
get_http_200_response_code
http_response_code
response_http
response_http_2
fun_awesome
fun_awesome
10_cool_dudes
20_cool_dudes
def convert(camel_str):
temp_list = []
for letter in camel_str:
if letter.islower():
temp_list.append(letter)
else:
temp_list.append('_')
temp_list.append(letter)
result = "".join(temp_list)
return result.lower()
# Copy and paste your camel case code in the string below
camelCaseCode ="""
cv2.Matx33d ComputeZoomMatrix(const cv2.Point2d & zoomCenter, double zoomRatio)
{
auto mat = cv2.Matx33d::eye();
mat(0, 0) = zoomRatio;
mat(1, 1) = zoomRatio;
mat(0, 2) = zoomCenter.x * (1. - zoomRatio);
mat(1, 2) = zoomCenter.y * (1. - zoomRatio);
return mat;
}
"""
import re
def snake_case(name):
s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', name)
return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
def lines(str):
return str.split("\n")
def unlines(lst):
return "\n".join(lst)
def words(str):
return str.split(" ")
def unwords(lst):
return " ".join(lst)
def map_partial(function):
return lambda values : [ function(v) for v in values]
import functools
def compose(*functions):
return functools.reduce(lambda f, g: lambda x: f(g(x)), functions, lambda x: x)
snake_case_code = compose(
unlines ,
map_partial(unwords),
map_partial(map_partial(snake_case)),
map_partial(words),
lines
)
print(snake_case_code(camelCaseCode))
>>> import re
>>> def camel_to_snake(string):
... groups = re.findall('([A-z0-9][a-z]*)', string)
... return '_'.join([i.lower() for i in groups])
...
>>> camel_to_snake('ABCPingPongByTheWay2KWhereIsOurBorderlands3???')
'a_b_c_ping_pong_by_the_way_2_k_where_is_our_borderlands_3'