例子:
>>> convert('CamelCase')
'camel_case'
例子:
>>> convert('CamelCase')
'camel_case'
当前回答
我不知道为什么这些都这么复杂。
对于大多数情况,简单的表达式([A-Z]+)就可以了
>>> 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 (?!^)
>>> re.sub('(?!^)([A-Z]+)', r'_\1','CamelCase').lower()
'camel_case'
>>> re.sub('(?!^)([A-Z]+)', r'_\1','CamelCamelCase').lower()
'camel_camel_case'
>>> re.sub('(?!^)([A-Z]+)', r'_\1','Camel2Camel2Case').lower()
'camel2_camel2_case'
>>> re.sub('(?!^)([A-Z]+)', r'_\1','getHTTPResponseCode').lower()
'get_httpresponse_code'
如果你想分离ALLCaps到all_caps,并期望字符串中的数字,你仍然不需要做两次单独的运行,只需使用|这个表达式((?<=[a-z0-9])[A-Z]|(?!^)[A-Z](?=[A-Z]))可以处理书中的几乎所有场景
>>> a = re.compile('((?<=[a-z0-9])[A-Z]|(?!^)[A-Z](?=[a-z]))')
>>> a.sub(r'_\1', 'getHTTPResponseCode').lower()
'get_http_response_code'
>>> a.sub(r'_\1', 'get2HTTPResponseCode').lower()
'get2_http_response_code'
>>> a.sub(r'_\1', 'get2HTTPResponse123Code').lower()
'get2_http_response123_code'
>>> a.sub(r'_\1', 'HTTPResponseCode').lower()
'http_response_code'
>>> a.sub(r'_\1', 'HTTPResponseCodeXYZ').lower()
'http_response_code_xyz'
这完全取决于你想要什么,所以使用最适合你需要的解决方案,因为它不应该过于复杂。
nJoy !
其他回答
def convert(name):
return reduce(
lambda x, y: x + ('_' if y.isupper() else '') + y,
name
).lower()
如果我们需要覆盖一个已经没有驼峰输入的情况:
def convert(name):
return reduce(
lambda x, y: x + ('_' if y.isupper() and not x.endswith('_') else '') + y,
name
).lower()
在标准库中没有,但我发现这个模块似乎包含您需要的功能。
以防有人需要转换一个完整的源文件,这里有一个脚本可以做到这一点。
# 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))
骆驼案变蛇案
import re
name = 'CamelCaseName'
name = re.sub(r'(?<!^)(?=[A-Z])', '_', name).lower()
print(name) # camel_case_name
如果你这样做了很多次,上面的速度很慢,提前编译正则表达式:
pattern = re.compile(r'(?<!^)(?=[A-Z])')
name = pattern.sub('_', name).lower()
为了处理更高级的情况(这是不可逆的了):
def camel_to_snake(name):
name = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', name)
return re.sub('([a-z0-9])([A-Z])', r'\1_\2', name).lower()
print(camel_to_snake('camel2_camel2_case')) # camel2_camel2_case
print(camel_to_snake('getHTTPResponseCode')) # get_http_response_code
print(camel_to_snake('HTTPResponseCodeXYZ')) # http_response_code_xyz
添加带有两个或两个以上下划线的also大小写:
def to_snake_case(name):
name = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', name)
name = re.sub('__([A-Z])', r'_\1', name)
name = re.sub('([a-z0-9])([A-Z])', r'\1_\2', name)
return name.lower()
斯内克案转帕斯卡案
name = 'snake_case_name'
name = ''.join(word.title() for word in name.split('_'))
print(name) # SnakeCaseName
避免使用库和正则表达式:
def camel_to_snake(s):
return ''.join(['_'+c.lower() if c.isupper() else c for c in s]).lstrip('_')
>>> camel_to_snake('ThisIsMyString')
'this_is_my_string'