python 中的join()
函数通过使用字符串分隔符连接给定 iterable 的所有元素来帮助创建新字符串。
**string.join(iterable)** #where iterable may be List, Tuple, String, Dictionary and Set.
join()
参数:join()
函数接受一个参数。如果可迭代表包含任何非字符串值,该函数将引发类型错误异常,
参数 | 描述 | 必需/可选 |
---|---|---|
可迭代的 | 所有返回值都是字符串的任何可迭代对象 | 需要 |
join()
返回值返回值始终是串联字符串。如果我们使用字典作为可迭代表,返回值将是键,而不是值。
| 投入 | 返回值 | | 可重复的 | 线 |
join()
方法的示例join()
方法在 Python 中是如何工作的? # .join() with lists
List = ['5', '4', '3', '2']
separator = ', '
print(separator.join(List))
# .join() with tuples
Tuple = ('5', '4', '3', '2')
print(separator.join(Tuple))
string1 = 'xyz'
string2 = '123'
# each element of string2 is separated by string1
# '1'+ 'xyz'+ '2'+ 'xyz'+ '3'
print('string1.join(string2):', string1.join(string2))
# each element of string1 is separated by string2
# 'x'+ '123'+ 'y'+ '123'+ 'z'
print('string2.join(string1):', string2.join(string1))
输出:
5, 4, 3, 2
5, 4, 3, 2
string1.join(string2): 1xyz2xyz3
string2.join(string1): x123y123z
join()
方法如何在 Python 中处理集合? # .join() with sets
num = {'5', '4', '3'}
separator = ', '
print(separator.join(num))
string = {'Apple', 'Orange', 'Grapes'}
separator = '->->'
print(separator.join(string))
输出:
5, 4, 3
Apple->->Orange->->Grapes
print(chr(-1))
print(chr(1114112))
输出:
ValueError: chr() arg not in range(0x110000)
ValueError: chr() arg not in range(0x110000)
join()
方法如何与字典一起工作? # .join() with dictionaries
dict = {'test': 1, 'with': 2}
seperator = '->'
# joins the keys only
print(seperator.join(dict))
dict = {1: 'test', 2: 'with'}
seperator = ', '
# this gives error since key isn't string
print(seperator.join(dict))
输出:
test->with
Traceback (most recent call last):
File "...", line 12, in <module>TypeError: sequence item 0: expected str instance, int found</module>
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