一、建立
s = "morra"
s = str("morra") #str()這種方法會自動找到str類裡的_init_方法去執行
----------------------------------------------------
def __init__(self, value='', encoding=None, errors='strict'):
"""
str(object='') -> str
str(bytes_or_buffer[, encoding[, errors]]) -> str
Create a new string object from the given object. If encoding or
errors is specified, then the object must expose a data buffer
that will be decoded using the given encoding and error handler.
Otherwise, returns the result of object.__str__() (if defined)
or repr(object).
encoding defaults to sys.getdefaultencoding().
errors defaults to 'strict'.
# (copied from class doc)
"""
pass
----------------------------------------------------
s = str()
s = str("morra")
s = str("morra",encoding='utf-8')二、常用功能
索引
s="hello"
print(s[0]) #h
print(s[1]) #e
print(s[2]) #l
print(s[3]) #l
print(s[4]) #o
print(s[5]) #報錯長度
len(s)
切片
s="hello"
print(s[0:2]) #0<=X<2，輸出“he”移除空白
strip()
分割
partition("字串"，"分割字元")、split()
split()的常見用法：
url = "www.google.com/login/ex"
a, b, c = url.split("/")
print(a, b, c) #www.google.com login ex
x = url.split("/")
print(x) #['www.google.com', 'login', 'ex']
p = url.split("/", -1)
print(p) #['www.google.com', 'login', 'ex']
y = url.split("/")[-1]
print(y) #ex
z = url.split("/", 1)
print(z) #['www.google.com', 'login/ex']三、輸出方式
python2.7
s = "你好"
for i in s:
print i
OUTPUT: #2.7預設以位元組的方式輸出
�
�
�
�
�
�python3.5
s = "你好"
for i in s:
print (i)
OUTPUT: #3.5預設以字元的方式輸出
你
好四、原始碼
class str(object):
"""
str(object='') -> str
str(bytes_or_buffer[, encoding[, errors]]) -> str
Create a new string object from the given object. If encoding or
errors is specified, then the object must expose a data buffer
that will be decoded using the given encoding and error handler.
Otherwise, returns the result of object.__str__() (if defined)
or repr(object).
encoding defaults to sys.getdefaultencoding().
errors defaults to 'strict'.
"""
def capitalize(self):
"""首字母大寫"""
"""
S.capitalize() -> str
Return a capitalized version of S, i.e. make the first character
have upper case and the rest lower case.
"""
return ""
def center(self, width, fillchar=None):
""" 內容居中，width：總長度；fillchar：空白處填充內容，預設無 """
"""
S.center(width[, fillchar]) -> str
Return S centered in a string of length width. Padding is
done using the specified fill character (default is a space)
"""
return ""
def count(self, sub, start=None, end=None):
"""
子序列個數
a = "hello,world"
ret1 = a.count("o")
ret2 = a.count("o",0,4) #計算"hell"裡"o"的個數
print(ret1)
print(ret2)
"""
"""
S.count(sub[, start[, end]]) -> int
Return the number of non-overlapping occurrences of substring sub in
string S[start:end]. Optional arguments start and end are
interpreted as in slice notation.
"""
return 0
def encode(self, encoding='utf-8', errors='strict'):
"""編碼"""
"""
S.encode(encoding='utf-8', errors='strict') -> bytes
Encode S using the codec registered for encoding. Default encoding
is 'utf-8'. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
'xmlcharrefreplace' as well as any other name registered with
codecs.register_error that can handle UnicodeEncodeErrors.
"""
return b""
def endswith(self, suffix, start=None, end=None):
"""在指定的範圍內判斷是否以某一個字元結尾"""
"""
S.endswith(suffix[, start[, end]]) -> bool
Return True if S ends with the specified suffix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
suffix can also be a tuple of strings to try.
"""
return False
def find(self, sub, start=None, end=None):
"""尋找子序列的位置，如果沒找到，返回-1"""
"""
S.find(sub[, start[, end]]) -> int
Return the lowest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation.
Return -1 on failure.
"""
return 0
def format(self, *args, **kwargs): # known special case of str.format
"""
字串格式化
s = "hello {0}，age:{1}"
new = s.format('Morra',99)
print(new)
"""
"""
S.format(*args, **kwargs) -> str
Return a formatted version of S, using substitutions from args and kwargs.
The substitutions are identified by braces ('{' and '}').
"""
pass
def format_map(self, mapping):
"""
S.format_map(mapping) -> str
Return a formatted version of S, using substitutions from mapping.
The substitutions are identified by braces ('{' and '}').
"""
return ""
def index(self, sub, start=None, end=None):
"""尋找子序列位置，如果沒找到，則報錯"""
"""
S.index(sub[, start[, end]]) -> int
Like S.find() but raise ValueError when the substring is not found.
"""
return 0
def isalnum(self):
"""判斷是否是字母和數字"""
"""
S.isalnum() -> bool
Return True if all characters in S are alphanumeric
and there is at least one character in S, False otherwise.
"""
return False
def isalpha(self):
"""判斷是否是字母"""
"""
S.isalpha() -> bool
Return True if all characters in S are alphabetic
and there is at least one character in S, False otherwise.
"""
return False
def isdecimal(self):
"""判斷是否為小數"""
"""
S.isdecimal() -> bool
Return True if there are only decimal characters in S,
False otherwise.
"""
return False
def isdigit(self):
"""判斷是否是數字"""
"""
S.isdigit() -> bool
Return True if all characters in S are digits
and there is at least one character in S, False otherwise.
"""
return False
def isidentifier(self):
"""
S.isidentifier() -> bool
Return True if S is a valid identifier according
to the language definition.
Use keyword.iskeyword() to test for reserved identifiers
such as "def" and "class".
"""
return False
def islower(self):
"""判斷是否存在小寫"""
"""
S.islower() -> bool
Return True if all cased characters in S are lowercase and there is
at least one cased character in S, False otherwise.
"""
return False
def isnumeric(self):
"""
S.isnumeric() -> bool
Return True if there are only numeric characters in S,
False otherwise.
"""
return False
def isprintable(self):
"""
S.isprintable() -> bool
Return True if all characters in S are considered
printable in repr() or S is empty, False otherwise.
"""
return False
def isspace(self):
"""判斷是否全部為小寫"""
"""
S.isspace() -> bool
Return True if all characters in S are whitespace
and there is at least one character in S, False otherwise.
"""
return False
def istitle(self):
"""判斷是否是標題"""
"""
S.istitle() -> bool
Return True if S is a titlecased string and there is at least one
character in S, i.e. upper- and titlecase characters may only
follow uncased characters and lowercase characters only cased ones.
Return False otherwise.
"""
return False
def isupper(self):
"""判斷是否全部為大寫"""
"""
S.isupper() -> bool
Return True if all cased characters in S are uppercase and there is
at least one cased character in S, False otherwise.
"""
return False
def join(self, iterable):
"""
連結方法,可使用可迭代的變數
li = ['a','b']
s = "$".join(li)
print(s) #a$b
"""
"""
S.join(iterable) -> str
Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
"""
return ""
def ljust(self, width, fillchar=None):
"""內容左對齊，右側填充，與center用法類似"""
"""
S.ljust(width[, fillchar]) -> str
Return S left-justified in a Unicode string of length width. Padding is
done using the specified fill character (default is a space).
"""
return ""
def lower(self):
"""使字母小寫"""
"""
S.lower() -> str
Return a copy of the string S converted to lowercase.
"""
return ""
def lstrip(self, chars=None):
"""移除左邊空格"""
"""
S.lstrip([chars]) -> str
Return a copy of the string S with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
return ""
def maketrans(self, *args, **kwargs):
"""
Return a translation table usable for str.translate().
If there is only one argument, it must be a dictionary mapping Unicode
ordinals (integers) or characters to Unicode ordinals, strings or None.
Character keys will be then converted to ordinals.
If there are two arguments, they must be strings of equal length, and
in the resulting dictionary, each character in x will be mapped to the
character at the same position in y. If there is a third argument, it
must be a string, whose characters will be mapped to None in the result.
"""
pass
def partition(self, sep):
"""以sep進行分割，輸出元組"""
"""
S.partition(sep) -> (head, sep, tail)
Search for the separator sep in S, and return the part before it,
the separator itself, and the part after it. If the separator is not
found, return S and two empty strings.
"""
pass
def replace(self, old, new, count=None):
"""
替換
s4="hello MORRA hello"
ret = s4.replace("he","BB")
ret2 = s4.replace("he","BB",1) #替換一次
"""
"""
S.replace(old, new[, count]) -> str
Return a copy of S with all occurrences of substring
old replaced by new. If the optional argument count is
given, only the first count occurrences are replaced.
"""
return ""
def rfind(self, sub, start=None, end=None):
"""從右往左找，參見find（）"""
"""
S.rfind(sub[, start[, end]]) -> int
Return the highest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation.
Return -1 on failure.
"""
return 0
def rindex(self, sub, start=None, end=None):
"""尋找子序列，如果沒有則報錯"""
"""
S.rindex(sub[, start[, end]]) -> int
Like S.rfind() but raise ValueError when the substring is not found.
"""
return 0
def rjust(self, width, fillchar=None):
"""右對齊"""
"""
S.rjust(width[, fillchar]) -> str
Return S right-justified in a string of length width. Padding is
done using the specified fill character (default is a space).
"""
return ""
def rpartition(self, sep):
"""
S.rpartition(sep) -> (head, sep, tail)
Search for the separator sep in S, starting at the end of S, and return
the part before it, the separator itself, and the part after it. If the
separator is not found, return two empty strings and S.
"""
pass
def rstrip(self, chars=None):
"""移除右邊邊空格"""
"""
S.rstrip([chars]) -> str
Return a copy of the string S with trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
return ""
def split(self, sep=None, maxsplit=-1):
"""
分割字元
str.split(str="", num=string.count(str))
str -- 分隔符，預設為空格
num -- 分割次數。
"""
"""
S.split(sep=None, maxsplit=-1) -> list of strings
Return a list of the words in S, using sep as the
delimiter string. If maxsplit is given, at most maxsplit
splits are done. If sep is not specified or is None, any
whitespace string is a separator and empty strings are
removed from the result.
"""
return []
def splitlines(self, keepends=None):
"""
S.splitlines([keepends]) -> list of strings
Return a list of the lines in S, breaking at line boundaries.
Line breaks are not included in the resulting list unless keepends
is given and true.
"""
return []
def startswith(self, prefix, start=None, end=None):
"""以XX開始，參見endswith"""
"""
S.startswith(prefix[, start[, end]]) -> bool
Return True if S starts with the specified prefix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
prefix can also be a tuple of strings to try.
"""
return False
def strip(self, chars=None):
"""移除兩邊空格"""
"""
S.strip([chars]) -> str
Return a copy of the string S with leading and trailing
whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
return ""
def swapcase(self):
"""大小寫翻轉"""
"""
S.swapcase() -> str
Return a copy of S with uppercase characters converted to lowercase
and vice versa.
"""
return ""
def title(self):
"""標題化，即首字母大寫"""
"""
S.title() -> str
Return a titlecased version of S, i.e. words start with title case
characters, all remaining cased characters have lower case.
"""
return ""
def translate(self, table):
"""
S.translate(table) -> str
Return a copy of the string S in which each character has been mapped
through the given translation table. The table must implement
lookup/indexing via __getitem__, for instance a dictionary or list,
mapping Unicode ordinals to Unicode ordinals, strings, or None. If
this operation raises LookupError, the character is left untouched.
Characters mapped to None are deleted.
"""
return ""
def upper(self):
"""字母大寫,在做驗證碼的時候比較有用"""
"""
S.upper() -> str
Return a copy of S converted to uppercase.
"""
return ""
def zfill(self, width):
"""
S.zfill(width) -> str
Pad a numeric string S with zeros on the left, to fill a field
of the specified width. The string S is never truncated.
"""
return ""
def __add__(self, *args, **kwargs):
""" Return self+value. """
pass
def __contains__(self, *args, **kwargs):
""" Return key in self. """
pass
def __eq__(self, *args, **kwargs):
""" Return self==value. """
pass
def __format__(self, format_spec):
"""
S.__format__(format_spec) -> str
Return a formatted version of S as described by format_spec.
"""
return ""
def __getattribute__(self, *args, **kwargs):
""" Return getattr(self, name). """
pass
def __getitem__(self, *args, **kwargs):
""" Return self[key]. """
pass
def __getnewargs__(self, *args, **kwargs):
pass
def __ge__(self, *args, **kwargs):
""" Return self>=value. """
pass
def __gt__(self, *args, **kwargs):
""" Return self>value. """
pass
def __hash__(self, *args, **kwargs):
""" Return hash(self). """
pass
def __init__(self, value='', encoding=None, errors='strict'): # known special case of str.__init__
"""
str(object='') -> str
str(bytes_or_buffer[, encoding[, errors]]) -> str
Create a new string object from the given object. If encoding or
errors is specified, then the object must expose a data buffer
that will be decoded using the given encoding and error handler.
Otherwise, returns the result of object.__str__() (if defined)
or repr(object).
encoding defaults to sys.getdefaultencoding().
errors defaults to 'strict'.
# (copied from class doc)
"""
pass
def __iter__(self, *args, **kwargs):
""" Implement iter(self). """
pass
def __len__(self, *args, **kwargs):
""" Return len(self). """
pass
def __le__(self, *args, **kwargs):
""" Return self<=value. """
pass
def __lt__(self, *args, **kwargs):
""" Return self<value. """
pass
def __mod__(self, *args, **kwargs):
""" Return self%value. """
pass
def __mul__(self, *args, **kwargs):
""" Return self*value.n """
pass
@staticmethod # known case of __new__
def __new__(*args, **kwargs):
""" Create and return a new object. See help(type) for accurate signature. """
pass
def __ne__(self, *args, **kwargs):
""" Return self!=value. """
pass
def __repr__(self, *args, **kwargs):
""" Return repr(self). """
pass
def __rmod__(self, *args, **kwargs):
""" Return value%self. """
pass
def __rmul__(self, *args, **kwargs):
""" Return self*value. """
pass
def __sizeof__(self):
""" S.__sizeof__() -> size of S in memory, in bytes """
pass
def __str__(self, *args, **kwargs):
""" Return str(self). """
pass