I am trying to print out the contents of a set and when I do, I get the set identifier in the print output. For example, this is my output set(['a', 'c', 'b', 'e', 'd', 'f', 'gg', 'ff', 'jk'])" for the code below. I want to get rid of the word set. My code is very simple and is below.
infile = open("P3TestData.txt", "r")
words = set(infile.read().split())
print words
Here is my output again for easy reference: set(['a', 'c', 'b', 'e', 'd', 'f', 'gg', 'ff', 'jk'])
You could convert the set to a list, just for printing:
print list(words)
or you could use str.join() to join the contents of the set with a comma:
print ', '.join(words)
The print statement uses set's implementation of __str__(). You can:
Roll out your own printing function, instead of using print. A simple way to get a nicer formatting may be to use list's implementation of __str__() instead:
print list(my_set)
Override the __str__() implementation in your own set subclass.
这个子类适用于数字和字符：
class sset(set):
def __str__(self):
return ', '.join([str(i) for i in self])
print set([1,2,3])
print sset([1,2,3])
输出
set([1, 2, 3])
1, 2, 3
如果你想要花括号，你可以这样做：
>>> s={1,2,3}
>>> s
set([1, 2, 3])
>>> print list(s).__str__().replace('[','{').replace(']','}')
{1, 2, 3}
或者，使用格式：
>>> print '{{{}}}'.format(', '.join(str(e) for e in set([1,'2',3.0])))
{3.0, 1, 2}
如果在 Python 3 中打印一组数字，您也可以使用切片。
Python 3.3.5
>>> s = {1, 2, 3, 4}
>>> s
{1, 2, 3, 4}
>>> str(s)[1:-1]
'1, 2, 3, 4'
这在移植回 Python2 时翻译得不好......
Python 2.7.6
>>> s = {1, 2, 3, 4}
>>> str(s)[1:-1]
'et([1, 2, 3, 4]'
>>> str(s)[5:-2]
'1, 2, 3, 4'
另一方面，对于join()整数值，您必须先转换为字符串：
Python 2.7.6
>>> strings = {'a', 'b', 'c'}
>>> ', '.join(strings)
'a, c, b'
>>> numbers = {1, 2, 3, 4}
>>> ', '.join(numbers)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: sequence item 0: expected string, int found
>>> ', '.join(str(number) for number in numbers)
'1, 2, 3, 4'
然而，这仍然比切片更正确。