我如何打印一个整数与逗号作为千分隔符?
1234567 ⟶ 1,234,567
在句点和逗号之间决定不需要特定于区域设置。
我如何打印一个整数与逗号作为千分隔符?
1234567 ⟶ 1,234,567
在句点和逗号之间决定不需要特定于区域设置。
当前回答
下面是移除不相关部分并稍微清理后的地区分组代码:
(以下仅适用于整数)
def group(number):
s = '%d' % number
groups = []
while s and s[-1].isdigit():
groups.append(s[-3:])
s = s[:-3]
return s + ','.join(reversed(groups))
>>> group(-23432432434.34)
'-23,432,432,434'
这里已经有一些很好的答案了。我只是想补充一下,以备将来参考。在python 2.7中,将有一个用于千位分隔符的格式说明符。根据python文档,它是这样工作的
>>> '{:20,.2f}'.format(f)
'18,446,744,073,709,551,616.00'
在python3.1中,你可以这样做:
>>> format(1234567, ',d')
'1,234,567'
其他回答
下面是一行正则表达式替换:
re.sub("(\d)(?=(\d{3})+(?!\d))", r"\1,", "%d" % val)
仅适用于积分输出:
import re
val = 1234567890
re.sub("(\d)(?=(\d{3})+(?!\d))", r"\1,", "%d" % val)
# Returns: '1,234,567,890'
val = 1234567890.1234567890
# Returns: '1,234,567,890'
或者对于小于4位的浮点数,将格式说明符更改为%.3f:
re.sub("(\d)(?=(\d{3})+(?!\d))", r"\1,", "%.3f" % val)
# Returns: '1,234,567,890.123'
注意:不能正确工作与超过三个十进制数字,因为它将尝试分组小数部分:
re.sub("(\d)(?=(\d{3})+(?!\d))", r"\1,", "%.5f" % val)
# Returns: '1,234,567,890.12,346'
它是如何工作的
让我们来分析一下:
re.sub(pattern, repl, string)
pattern = \
"(\d) # Find one digit...
(?= # that is followed by...
(\d{3})+ # one or more groups of three digits...
(?!\d) # which are not followed by any more digits.
)",
repl = \
r"\1,", # Replace that one digit by itself, followed by a comma,
# and continue looking for more matches later in the string.
# (re.sub() replaces all matches it finds in the input)
string = \
"%d" % val # Format the string as a decimal to begin with
下面是另一个使用生成器函数处理整数的变体:
def ncomma(num):
def _helper(num):
# assert isinstance(numstr, basestring)
numstr = '%d' % num
for ii, digit in enumerate(reversed(numstr)):
if ii and ii % 3 == 0 and digit.isdigit():
yield ','
yield digit
return ''.join(reversed([n for n in _helper(num)]))
下面是一个测试:
>>> for i in (0, 99, 999, 9999, 999999, 1000000, -1, -111, -1111, -111111, -1000000):
... print i, ncomma(i)
...
0 0
99 99
999 999
9999 9,999
999999 999,999
1000000 1,000,000
-1 -1
-111 -111
-1111 -1,111
-111111 -111,111
-1000000 -1,000,000
我有这个代码的python 2和python 3版本。我知道这个问题是关于python2的,但是现在(8年过去了,哈哈)人们可能会使用python3。Python 3代码:
import random
number = str(random.randint(1, 10000000))
comma_placement = 4
print('The original number is: {}. '.format(number))
while True:
if len(number) % 3 == 0:
for i in range(0, len(number) // 3 - 1):
number = number[0:len(number) - comma_placement + 1] + ',' + number[len(number) - comma_placement + 1:]
comma_placement = comma_placement + 4
else:
for i in range(0, len(number) // 3):
number = number[0:len(number) - comma_placement + 1] + ',' + number[len(number) - comma_placement + 1:]
break
print('The new and improved number is: {}'.format(number))
Python 2代码:(编辑。python代码不能工作。我认为语法是不同的)。
import random
number = str(random.randint(1, 10000000))
comma_placement = 4
print 'The original number is: %s.' % (number)
while True:
if len(number) % 3 == 0:
for i in range(0, len(number) // 3 - 1):
number = number[0:len(number) - comma_placement + 1] + ',' + number[len(number) - comma_placement + 1:]
comma_placement = comma_placement + 4
else:
for i in range(0, len(number) // 3):
number = number[0:len(number) - comma_placement + 1] + ',' + number[len(number) - comma_placement + 1:]
break
print 'The new and improved number is: %s.' % (number)
你也可以使用'{:n}'。区域设置表示的格式(值)。我认为这是最简单的现场解决方案。
有关更多信息,请在Python DOC中搜索数千个。
对于货币,可以使用locale。货币,设置标志分组:
Code
import locale
locale.setlocale( locale.LC_ALL, '' )
locale.currency( 1234567.89, grouping = True )
输出
'Portuguese_Brazil.1252'
'R$ 1.234.567,89'
下面是移除不相关部分并稍微清理后的地区分组代码:
(以下仅适用于整数)
def group(number):
s = '%d' % number
groups = []
while s and s[-1].isdigit():
groups.append(s[-3:])
s = s[:-3]
return s + ','.join(reversed(groups))
>>> group(-23432432434.34)
'-23,432,432,434'
这里已经有一些很好的答案了。我只是想补充一下,以备将来参考。在python 2.7中,将有一个用于千位分隔符的格式说明符。根据python文档,它是这样工作的
>>> '{:20,.2f}'.format(f)
'18,446,744,073,709,551,616.00'
在python3.1中,你可以这样做:
>>> format(1234567, ',d')
'1,234,567'