数字函数
pycharm中使用ctrl + 鼠标左键查看详细的函数
int将字符串转换为int
（注意：input输入的都是字符串即使你输入的是数字，也需要使用int函数将字符串转为为数字）
#!/usr/bin/env python3 # -*- coding: UTF-8 -*- num = "123" print(type(num),num) a = int(num) print(type(a),num) 输出结果： D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py <class 'str'> 123 <class 'int'> 123
bit_lenght
当前数字的二进制，至少用n位表示
#!/usr/bin/env python3 # -*- coding: UTF-8 -*- num = 1 print(num.bit_length()) num = 2 print(num.bit_length()) num = 3 print(num.bit_length()) num = 4 print(num.bit_length()) num = 5 print(num.bit_length()) 结果： D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py 1 2 2 3 3
字符函数
str ：ctrl+鼠标左键查看详细信息
#首字母大写 name = "hang zhou" print(name.capitalize()) 结果： D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py Hang zhou
#返回所有字符串小写 #casefold 和 lower都可以，一般使用lower即可，casefold更加强大 name = "hAng Zhou" print(name.casefold()) print(name.lower()) 结果： D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py hang zhou hang zhou
#设置宽度，并将内容居中
#20表示总宽度，* 表示使用什么字符填充，只能是一个字符，默认是空字符
name = "hang zhou"
print(name.center(20))
print(name.center(20,"*"))
print(name.center(20,"中"))
结果：
D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py
hang zhou
*****hang zhou******
中中中中中hang zhou中中中中中中
Process finished with exit code 0
#查找字符串出现的次数
#后面的0表示起始位置是第一个字符，12表示结束位置是低12个字符，前开后闭的区间
name = "hang zhou hang"
print(name.count('a'))
print(name.count('an'))
print(name.count('ag'))
print(name.count("an",0,12))
结果：
D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py
2
2
0
1
Process finished with exit code 0
#查询是否以某个字符串开头或结尾，是则True，否这False
name = "hang zhou"
print(name.startswith("ha"))
print(name.endswith("ou"))
结果
D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py
True
True
Process finished with exit code 0
#查询某个字符串出现的位置，未出现显示-1,index函数也是，但是index不存在则报错，不建议使用
name = "hang zhou"
print(name.find("g"))
print(name.find("t"))
结果
D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py
3
-1
Process finished with exit code 0
#格式化，将一个字符串中的占位符替换为指定的值
test = 'i am {name}, age {num}'
v = test.format(name='hangzhou',num=100)
print(v)
#或者
test = 'i an {0}, age {1}'
v = test.format('hangz',200)
print(v)
#格式化传入的值
test = 'i am {name}, age {num}'
v1 = test.format(name='df',num=10)
v2 = test.format_map({"name": 'shanghai',"num": 300})
print(v1,v2)
结果
D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py
i am hangzhou, age 100
i an hangz, age 200
i am df, age 10 i am shanghai, age 300
# 字符串是否只包含字母和数字 test = '124' print(test.isalnum()) test = 'qwrer124' print(test.isalnum()) test = "asfa_123" print(test.isalnum()) test = "asadg" print(test.isalnum()) 结果： D:\pythonProject\python3\venv\Scripts\python.exe D:\pythonProject\python3\day10\s2.py True True False True
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, *args, **kwargs): # real signature unknown
"""
Return a capitalized version of the string.
More specifically, make the first character have upper case and the rest lower
case.
"""
pass
def casefold(self, *args, **kwargs): # real signature unknown
""" Return a version of the string suitable for caseless comparisons. """
pass
def center(self, *args, **kwargs): # real signature unknown
"""
Return a centered string of length width.
Padding is done using the specified fill character (default is a space).
"""
pass
def count(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
"""
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, *args, **kwargs): # real signature unknown
"""
Encode the string using the codec registered for encoding.
encoding
The encoding in which to encode the string.
errors
The error handling scheme to use for encoding errors.
The 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.
"""
pass
def endswith(self, suffix, start=None, end=None): # real signature unknown; restored from __doc__
"""
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 expandtabs(self, *args, **kwargs): # real signature unknown
"""
Return a copy where all tab characters are expanded using spaces.
If tabsize is not given, a tab size of 8 characters is assumed.
"""
pass
def find(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
"""
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
"""
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): # real signature unknown; restored from __doc__
"""
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): # real signature unknown; restored from __doc__
"""
S.index(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.
Raises ValueError when the substring is not found.
"""
return 0
def isalnum(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is an alpha-numeric string, False otherwise.
A string is alpha-numeric if all characters in the string are alpha-numeric and
there is at least one character in the string.
"""
pass
def isalpha(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is an alphabetic string, False otherwise.
A string is alphabetic if all characters in the string are alphabetic and there
is at least one character in the string.
"""
pass
def isascii(self, *args, **kwargs): # real signature unknown
"""
Return True if all characters in the string are ASCII, False otherwise.
ASCII characters have code points in the range U+0000-U+007F.
Empty string is ASCII too.
"""
pass
def isdecimal(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a decimal string, False otherwise.
A string is a decimal string if all characters in the string are decimal and
there is at least one character in the string.
"""
pass
def isdigit(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a digit string, False otherwise.
A string is a digit string if all characters in the string are digits and there
is at least one character in the string.
"""
pass
def isidentifier(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a valid Python identifier, False otherwise.
Call keyword.iskeyword(s) to test whether string s is a reserved identifier,
such as "def" or "class".
"""
pass
def islower(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a lowercase string, False otherwise.
A string is lowercase if all cased characters in the string are lowercase and
there is at least one cased character in the string.
"""
pass
def isnumeric(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a numeric string, False otherwise.
A string is numeric if all characters in the string are numeric and there is at
least one character in the string.
"""
pass
def isprintable(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is printable, False otherwise.
A string is printable if all of its characters are considered printable in
repr() or if it is empty.
"""
pass
def isspace(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a whitespace string, False otherwise.
A string is whitespace if all characters in the string are whitespace and there
is at least one character in the string.
"""
pass
def istitle(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is a title-cased string, False otherwise.
In a title-cased string, upper- and title-case characters may only
follow uncased characters and lowercase characters only cased ones.
"""
pass
def isupper(self, *args, **kwargs): # real signature unknown
"""
Return True if the string is an uppercase string, False otherwise.
A string is uppercase if all cased characters in the string are uppercase and
there is at least one cased character in the string.
"""
pass
def join(self, ab=None, pq=None, rs=None): # real signature unknown; restored from __doc__
"""
Concatenate any number of strings.
The string whose method is called is inserted in between each given string.
The result is returned as a new string.
Example: '.'.join(['ab', 'pq', 'rs']) -> 'ab.pq.rs'
"""
pass
def ljust(self, *args, **kwargs): # real signature unknown
"""
Return a left-justified string of length width.
Padding is done using the specified fill character (default is a space).
"""
pass
def lower(self, *args, **kwargs): # real signature unknown
""" Return a copy of the string converted to lowercase. """
pass
def lstrip(self, *args, **kwargs): # real signature unknown
"""
Return a copy of the string with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
pass
def maketrans(self, *args, **kwargs): # real signature unknown
"""
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, *args, **kwargs): # real signature unknown
"""
Partition the string into three parts using the given separator.
This will search for the separator in the string. If the separator is found,
returns a 3-tuple containing the part before the separator, the separator
itself, and the part after it.
If the separator is not found, returns a 3-tuple containing the original string
and two empty strings.
"""
pass
def removeprefix(self, *args, **kwargs): # real signature unknown
"""
Return a str with the given prefix string removed if present.
If the string starts with the prefix string, return string[len(prefix):].
Otherwise, return a copy of the original string.
"""
pass
def removesuffix(self, *args, **kwargs): # real signature unknown
"""
Return a str with the given suffix string removed if present.
If the string ends with the suffix string and that suffix is not empty,
return string[:-len(suffix)]. Otherwise, return a copy of the original
string.
"""
pass
def replace(self, *args, **kwargs): # real signature unknown
"""
Return a copy with all occurrences of substring old replaced by new.
count
Maximum number of occurrences to replace.
-1 (the default value) means replace all occurrences.
If the optional argument count is given, only the first count occurrences are
replaced.
"""
pass
def rfind(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
"""
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): # real signature unknown; restored from __doc__
"""
S.rindex(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.
Raises ValueError when the substring is not found.
"""
return 0
def rjust(self, *args, **kwargs): # real signature unknown
"""
Return a right-justified string of length width.
Padding is done using the specified fill character (default is a space).
"""
pass
def rpartition(self, *args, **kwargs): # real signature unknown
"""
Partition the string into three parts using the given separator.
This will search for the separator in the string, starting at the end. If
the separator is found, returns a 3-tuple containing the part before the
separator, the separator itself, and the part after it.
If the separator is not found, returns a 3-tuple containing two empty strings
and the original string.
"""
pass
def rsplit(self, *args, **kwargs): # real signature unknown
"""
Return a list of the words in the string, using sep as the delimiter string.
sep
The delimiter according which to split the string.
None (the default value) means split according to any whitespace,
and discard empty strings from the result.
maxsplit
Maximum number of splits to do.
-1 (the default value) means no limit.
Splits are done starting at the end of the string and working to the front.
"""
pass
def rstrip(self, *args, **kwargs): # real signature unknown
"""
Return a copy of the string with trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
pass
def split(self, *args, **kwargs): # real signature unknown
"""
Return a list of the words in the string, using sep as the delimiter string.
sep
The delimiter according which to split the string.
None (the default value) means split according to any whitespace,
and discard empty strings from the result.
maxsplit
Maximum number of splits to do.
-1 (the default value) means no limit.
"""
pass
def splitlines(self, *args, **kwargs): # real signature unknown
"""
Return a list of the lines in the string, breaking at line boundaries.
Line breaks are not included in the resulting list unless keepends is given and
true.
"""
pass
def startswith(self, prefix, start=None, end=None): # real signature unknown; restored from __doc__
"""
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, *args, **kwargs): # real signature unknown
"""
Return a copy of the string with leading and trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
"""
pass
def swapcase(self, *args, **kwargs): # real signature unknown
""" Convert uppercase characters to lowercase and lowercase characters to uppercase. """
pass
def title(self, *args, **kwargs): # real signature unknown
"""
Return a version of the string where each word is titlecased.
More specifically, words start with uppercased characters and all remaining
cased characters have lower case.
"""
pass
def translate(self, *args, **kwargs): # real signature unknown
"""
Replace each character in the string using the given translation table.
table
Translation table, which must be a mapping of Unicode ordinals to
Unicode ordinals, strings, or None.
The table must implement lookup/indexing via __getitem__, for instance a
dictionary or list. If this operation raises LookupError, the character is
left untouched. Characters mapped to None are deleted.
"""
pass
def upper(self, *args, **kwargs): # real signature unknown
""" Return a copy of the string converted to uppercase. """
pass
def zfill(self, *args, **kwargs): # real signature unknown
"""
Pad a numeric string with zeros on the left, to fill a field of the given width.
The string is never truncated.
"""
pass
def __add__(self, *args, **kwargs): # real signature unknown
""" Return self+value. """
pass
def __contains__(self, *args, **kwargs): # real signature unknown
""" Return key in self. """
pass
def __eq__(self, *args, **kwargs): # real signature unknown
""" Return self==value. """
pass
def __format__(self, *args, **kwargs): # real signature unknown
""" Return a formatted version of the string as described by format_spec. """
pass
def __getattribute__(self, *args, **kwargs): # real signature unknown
""" Return getattr(self, name). """
pass
def __getitem__(self, *args, **kwargs): # real signature unknown
""" Return self[key]. """
pass
def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass
def __ge__(self, *args, **kwargs): # real signature unknown
""" Return self>=value. """
pass
def __gt__(self, *args, **kwargs): # real signature unknown
""" Return self>value. """
pass
def __hash__(self, *args, **kwargs): # real signature unknown
""" 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): # real signature unknown
""" Implement iter(self). """
pass
def __len__(self, *args, **kwargs): # real signature unknown
""" Return len(self). """
pass
def __le__(self, *args, **kwargs): # real signature unknown
""" Return self<=value. """
pass
def __lt__(self, *args, **kwargs): # real signature unknown
""" Return self<value. """
pass
def __mod__(self, *args, **kwargs): # real signature unknown
""" Return self%value. """
pass
def __mul__(self, *args, **kwargs): # real signature unknown
""" Return self*value. """
pass
@staticmethod # known case of __new__
def __new__(*args, **kwargs): # real signature unknown
""" Create and return a new object. See help(type) for accurate signature. """
pass
def __ne__(self, *args, **kwargs): # real signature unknown
""" Return self!=value. """
pass
def __repr__(self, *args, **kwargs): # real signature unknown
""" Return repr(self). """
pass
def __rmod__(self, *args, **kwargs): # real signature unknown
""" Return value%self. """
pass
def __rmul__(self, *args, **kwargs): # real signature unknown
""" Return value*self. """
pass
def __sizeof__(self, *args, **kwargs): # real signature unknown
""" Return the size of the string in memory, in bytes. """
pass
def __str__(self, *args, **kwargs): # real signature unknown
""" Return str(self). """
pass
标签：real,函数,unknown,self,数字,signature,字符串,def,string From： https://www.cnblogs.com/zhazhadba/p/16825400.html