>>> "www.dhdzp.com" #字符串使用單引號（'）或雙引號（"）表示
'www.dhdzp.com'
>>> 'www.dhdzp.com'
'www.dhdzp.com'
>>> "www."+"jb51"+".net" #字符串可以用“+”號連接
'www.dhdzp.com'
>>> "#"*10 #字符串可以使用“*”來代表重復次數(shù)
'##########'
>>> "What's your name?" #單引號中可以直接使用雙引號，同理雙引號中也可以直接使用單引號
"What's your name?"
>>> path = r"C:\newfile" #此處r開頭表示原始字符串，里面放置的內容都是原樣輸出
>>> print(path)
C:\newfile

>>> str1 = "python test"
>>> "test" in str1 #這里in用來判斷元素是否在序列中
True
>>> len(str1) #這里len()函數(shù)求字符串長度
11
>>> max(str1)
'y'
>>> min(str1)
' '

>>> "I like %s" % "python" #使用%進行格式化輸出的經典表示方式
'I like python'
>>> dir(str) #列出字符串所有屬性與方法
['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isdecimal', 'isdigit', 'isidentifier', 'islower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']

>>> str = "I like {1} and {2}" #這里{1}表示占位符（注意：這里得從{0}開始）
>>> str.format("python","PHP")
Traceback (most recent call last):
 File "<pyshell#5>", line 1, in <module>
  str.format("python","PHP")
IndexError: tuple index out of range
>>> str = "I like {0} and {1}"
>>> str.format("python","PHP")
'I like python and PHP'
>>> "I like {1} and {0}".format("python","PHP")
'I like PHP and python'
>>> "I like {0:20} and {1:>20}".format("python","PHP")#{0:20}表示第一個位置占據(jù)20個字符，并且左對齊。{1:>20}表示第二個位置占據(jù)20個字符，且右對齊
'I like python        and         PHP'
>>> "I like {0:.2} and {1:^10.2}".format("python","PHP")#{0:.2}表示第一個位置截取2個字符，左對齊。{1:^10.2}表示第二個位置占據(jù)10個字符，且截取2個字符，^表示居中
'I like py and   PH  '
>>> "age: {0:4d} height: {1:6.2f}".format("32","178.55") #這里應該是數(shù)字，不能用引號，否則會被當作字符串而報錯！
Traceback (most recent call last):
 File "<pyshell#0>", line 1, in <module>
  "age: {0:4d} height: {1:6.2f}".format("32","178.55")
ValueError: Unknown format code 'd' for object of type 'str'
>>> "age: {0:4d} height: {1:8.2f}".format(32,178.5523154) #這里4d表示長度為4個字符的整數(shù)，右對齊。8.2f表示長度為8，保留2位小數(shù)的浮點數(shù)，右對齊。
'age:  32 height:  178.55'

>>> "I like {str1} and {str2}".format(str1 = "python",str2 ="PHP")
'I like python and PHP'
>>> data = {"str1":"PHP","str2":"Python"}
>>> "I like {str1} and {str2}".format(**data)
'I like PHP and Python'

>>> # isalpha()判斷字符串是否全部為字母
>>> str1 = "I like python" #這里str1里面有空格
>>> str1.isalpha()
False
>>> str2 = "pythonDemo" #這里為全部是字母
>>> str2.isalpha()
True

>>> # split()分割字符串
>>> smp = "I like Python"
>>> smp.split(" ")
['I', 'like', 'Python']

>>> # strip()去除字符串兩端空格 ，類似的，lstrip去除左側空格，rstrip去除右側空格
>>> strDemo = "  python demo  "
>>> strDemo.strip() #類似于php中的trim()函數(shù)
'python demo'
>>> "****python**".strip("*") #strip()函數(shù)還可刪除指定字符
'python'

>>> #字符串拼接（對于+不適用的情況下可以使用）
>>> smp = "I like Python"
>>> c = smp.split(" ")
>>> c = "I like python".split()
>>> type(c) #這里檢測類型，可以看到c為列表
<class 'list'>
>>> "*".join(c)
'I*like*Python'
>>> " ".join(c)
'I like Python'
>>> " ".join(["I","Like","python"]) #這里可以直接使用列表作為join函數(shù)的參數(shù)
'I Like python'
>>> " ".join("abcd") #也可直接使用字符串作為join函數(shù)的參數(shù)
'a b c d'

>>> # count()函數(shù)統(tǒng)計指定字符串出現(xiàn)次數(shù)
>>> "like python,learn python".count("python")
2

>>> # find()函數(shù)查找指定字符串出現(xiàn)位置
>>> "python Demo".find("python")
0
>>> "python Demo".find("Demo")
7

>>> # replace(old,new)函數(shù)替換指定字符串(old)為新字符串(new)
>>> "I like php".replace("php","python")
'I like python'