在python中从数字列表打印格式化的数字范围字符串
我编写这个类是为了将数字列表压缩并扩展为序列字符串,包括步长值大于1时的步长值。代码仍然感觉笨拙。有这样的图书馆吗?可能更简单的代码在python中从数字列表打印格式化的数字范围字符串,python,Python,我编写这个类是为了将数字列表压缩并扩展为序列字符串,包括步长值大于1时的步长值。代码仍然感觉笨拙。有这样的图书馆吗?可能更简单的代码 import re class Foo( object ): def __init__( self, num_list ): self.num_list = sorted( list( set( [ int(n) for n in num_list ] ) ) ) # end def __init__ def gen_
import re
class Foo( object ):
def __init__( self, num_list ):
self.num_list = sorted( list( set( [ int(n) for n in num_list ] ) ) )
# end def __init__
def gen_seq_data( self ):
self.seq_data = list()
index_offset = None
backward_step_value = None
forward_step_value = None
sub_list = list()
sub_list_step_value = None
for index, num in enumerate( self.num_list ):
if index - 1 < 0:
backward_step_value = None
# end if
else:
backward_step_value = num - self.num_list[ index - 1 ]
# end else
try:
forward_step_value = self.num_list[ index + 1 ] - num
# end try
except IndexError:
forward_step_value = None
# end except
if backward_step_value is None:
sub_list.append( num )
# end if
elif backward_step_value == forward_step_value:
sub_list.append( num )
if forward_step_value is None:
self.seq_data.append( ( sub_list_step_value, sub_list ) )
# end if
# end if
elif backward_step_value == sub_list_step_value:
sub_list.append( num )
if sub_list:
self.seq_data.append( ( sub_list_step_value, sub_list ) )
# end if
sub_list = list()
# end elif
else:
if sub_list:
self.seq_data.append( ( sub_list_step_value, sub_list ) )
# end if
sub_list = [ num ]
if forward_step_value is None:
self.seq_data.append( ( sub_list_step_value, sub_list ) )
# end if
# end else
try:
sub_list_step_value = sub_list[ -1 ] - sub_list[ -2 ]
# end try
except IndexError:
sub_list_step_value = None
# end except
# end for
# end def gen_seq_object
def format_elements( self ):
format_elements = list()
for step, num_list in self.seq_data:
if step is None:
format_elements.append( '%s' % ( num_list[ 0 ] ) )
# end if
elif step == 1:
format_elements.append( '%s-%s' % ( num_list[ 0 ], num_list[ -1 ] ) )
# end elif
else:
format_elements.append( '%s-%sx%s' % ( num_list[ 0 ], num_list[ -1 ], step ) )
# end else
# end for
return format_elements
# end def format_range
def format_range( self ):
return ','.join( self.format_elements() )
# end def format_range
def expand_range( self ):
num_list = list()
for r_token in self.format_range().split( ',' ):
if r_token.isdigit():
num_list.append( int( r_token ) )
# end if
elif '-' in r_token:
if 'x' in r_token:
start, end, step = re.split( r'[-|x]', r_token )
num_list.extend( range( int( start ), int( end ) + 1, int( step ) ) )
# end if
else:
start, end = r_token.split( '-' )
num_list.extend( range( int( start ), int( end ) + 1 ) )
# end else
# end elif
# end for
return num_list
# end def expand_range
# end class Foo
一个。删除所有结束评论。它们毫无用处。你的缩进说明了一切。使用它
两个。不要把这当成一门课。它不是一个具有不同责任的不同对象。这只是一个算法。由函数组成。充其量它是一个包含所有静态方法的类
三个。永远不要这样做
for index, num in enumerate( self.num_list ):
if index - 1 < 0:
backward_step_value = None
# end if
else:
backward_step_value = num - self.num_list[ index - 1 ]
# end else
像这样的东西很少需要索引。事实上,拥有索引的唯一原因似乎是专门处理第一个元素
最后,这是一种“减少”。使用生成器函数
def reduce_list( some_list ):
v= min(some_list)
low, high = v, v
for v in sorted(some_list)[1:]:
if v == high+1:
high= high+1
else:
yield low, high
yield low, high
这可能会生成连续范围的列表。然后可以格式化这些文件
format_elements( reduce_list( some_list ) )
以下解决方案处理非连续范围,并保留忽略长度为2的范围的行为
def reduce_list(seq):
l = sorted(set(seq))
low = high = l[0]
step = None
for v in l[1:]:
if step is None or v - high == step:
# Extend the current range.
step = v - high
high = v
elif high - low == step:
# The current range only has two values. Yield the
# first value, and start a new range comprising the
# second value and the current value.
yield low, low, None
step = v - high
low = high
high = v
else:
# Yield the current range, and start a new one.
yield low, high, step
low = high = v
step = None
if high - low == step:
# The final range has only two values. Yield them
# individually.
yield low, low, None
step = None
low = high
yield low, high, step
def format_element(low, high, step):
if step is None:
assert low == high
return "%s" % (low,)
elif step == 1:
return "%s-%s" % (low, high)
else:
return "%s-%sx%s" % (low, high, step)
def format_list(seq):
return ','.join(format_element(*e) for e in seq)
下面是一些测试代码:
def test( *args ):
print args, "==", format_list(reduce_list(args))
test(1)
test(1, 2)
test(1, 2, 3)
test(0, 10)
test(0, 10, 20)
test(0, 10, 11, 12, 14, 16)
test(0, 2, 4, 8, 16, 32, 64)
test(0, 1, 3, 4, 6, 7, 9, 10)
test(0, 1, 3, 6, 10, 15, 21, 28)
哪些产出:
(1,) == 1
(1, 2) == 1,2
(1, 2, 3) == 1-3
(0, 10) == 0,10
(0, 10, 20) == 0-20x10
(0, 10, 11, 12, 14, 16) == 0,10-12,14,16
(0, 2, 4, 8, 16, 32, 64) == 0-4x2,8,16,32,64
(0, 1, 3, 4, 6, 7, 9, 10) == 0,1,3,4,6,7,9,10
(0, 1, 3, 6, 10, 15, 21, 28) == 0,1,3,6,10,15,21,28
请修正你的缩进。您的代码格式不正确。请(1)编辑问题,(2)阅读页面右侧的格式说明,(3)避免发布您拥有的每一段代码。你有什么问题?显示此问题的最小代码是什么?@user494203:扔掉“#end if”等行;它们毫无用处,尤其是在
elif
和else
之前发生的那些。如果您这样做,人们可能会更倾向于阅读您的代码并建议进一步的清除。此解决方案无法实现OP解决方案中最棘手的部分,即不仅识别连续范围,而且识别固定步长大于1的范围。@jchl:正确。重点不是修复他们的代码。重点是提供一种方法来修改代码,使其不那么“笨重”。将步骤作为变量而不是1
作为扩展应该不会太难。谢谢您的帮助。这些都是很好的解决方案。
def test( *args ):
print args, "==", format_list(reduce_list(args))
test(1)
test(1, 2)
test(1, 2, 3)
test(0, 10)
test(0, 10, 20)
test(0, 10, 11, 12, 14, 16)
test(0, 2, 4, 8, 16, 32, 64)
test(0, 1, 3, 4, 6, 7, 9, 10)
test(0, 1, 3, 6, 10, 15, 21, 28)
(1,) == 1
(1, 2) == 1,2
(1, 2, 3) == 1-3
(0, 10) == 0,10
(0, 10, 20) == 0-20x10
(0, 10, 11, 12, 14, 16) == 0,10-12,14,16
(0, 2, 4, 8, 16, 32, 64) == 0-4x2,8,16,32,64
(0, 1, 3, 4, 6, 7, 9, 10) == 0,1,3,4,6,7,9,10
(0, 1, 3, 6, 10, 15, 21, 28) == 0,1,3,6,10,15,21,28