Concatenate item in list to strings

2018-06-08 04:39:35

Is there a simpler way to concatenate string items in list into a single string?

Can I use the str.join() function to join items in list?

Eg this is the input ['this','is','a','sentence'] and this is the desired output this-is-a-sentence

sentence = ['this','is','a','sentence']
sent_str = ""
for i in sentence:
    sent_str += str(i) + "-"
sent_str = sent_str[:-1]
print sent_str

使用join ：

>>> sentence = ['this','is','a','sentence']
>>> '-'.join(sentence)
'this-is-a-sentence'

将python列表转换为字符串的更通用的方法是：

>>> my_lst = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> my_lst_str = ''.join(map(str, my_lst))
>>> print(my_lst_str)
'12345678910'

It's very useful for beginners to know why join is a string method

It's very strange at the beginning, but very useful after this.

The result of join is always a string, but the object to be joined can be of many types (generators, list, tuples, etc)

.join is faster because it allocates memory only once. Better than classical concatenation. extended explanation

Once you learn it, it's very comfortable and you can do tricks like this to add parentheses.

  >>> ",".join("12345").join(("(",")"))
  '(1,2,3,4,5)'

  >>> lista=["(",")"]
  >>> ",".join("12345").join(lista)
  '(1,2,3,4,5)'

链接地址: http://www.djcxy.com/p/24862.html