unicode 可以编译成 UTF-U GBK
即
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 a = '测试字符' #默认是utf-8 4 a_unicode = a.decode('utf-8') # decode是解码成unicode 括号是脚本内容的默认编码 即:将脚本内容的utf-8解码成unicode 5 a_gbk = a_unicode.encode('gbk') #encode是编码,将unicode的编码内容编码成指定的,这里是gbk 6 print(a_gbk) #用于终端打印 7 print(u"测试字符二") #3里面是字符串 2里面是unicode
#3版本直接将utf-8编码成GBK 不需要先转成unicode了
2、pycharm的基本配置
1、file-setings-editor- file && file encode template Python Script输入 以下内容作为声明模板
1 #!/usr/bin/env python 2 # _*_ coding:utf-8 _*_
2、View-Active Editor 勾选Use Soft Wraps 开启自动换行
3、在设置中,搜索encoding,可以修改编码规则
4、简单的快捷键
ctrl+/ 批量注释,取消注释
shift+方向键 选中
shift+tab 向左tab
5、
切换py版本
file -> settings ->project interpreter ->选择版本
3、运算符
1、算数运算:
2、比较运算:
3、赋值运算:
4、逻辑运算:
5、成员运算:
|
运算符 |
名称 |
说明 |
例子 |
|
+ |
加 |
两个对象相加 |
3 + 5得到8。'a' + 'b'得到'ab'。 |
|
- |
减 |
得到负数或是一个数减去另一个数 |
-5.2得到一个负数。50 - 24得到26。 |
|
* |
乘 |
两个数相乘或是返回一个被重复若干次的字符串 |
2 * 3得到6。'la' * 3得到'lalala'。 |
|
** |
幂 |
返回x的y次幂 |
3 ** 4得到81(即3 * 3 * 3 * 3) |
|
/ |
除 |
x除以y |
4/3得到1(整数的除法得到整数结果)。4.0/3或4/3.0得到1.3333333333333333 |
|
// |
取整除 |
返回商的整数部分 |
4 // 3.0得到1.0 |
|
% |
取模 |
返回除法的余数 |
8%3得到2。-25.5%2.25得到1.5 |
|
<< |
左移 |
把一个数的比特向左移一定数目(每个数在内存中都表示为比特或二进制数字,即0和1) |
2 << 2得到8。——2按比特表示为10 |
|
>> |
右移 |
把一个数的比特向右移一定数目 |
11 >> 1得到5。——11按比特表示为1011,向右移动1比特后得到101,即十进制的5。 |
|
& |
按位与 |
数的按位与 |
5 & 3得到1。 |
|
| |
按位或 |
数的按位或 |
5 | 3得到7。 |
|
^ |
按位异或 |
数的按位异或 |
5 ^ 3得到6 |
|
~ |
按位翻转 |
x的按位翻转是-(x+1) |
~5得到-6。 |
|
< |
小于 |
返回x是否小于y。所有比较运算符返回1表示真,返回0表示假。这分别与特殊的变量True和False等价。注意,这些变量名的大写。 |
5 < 3返回0(即False)而3 < 5返回1(即True)。比较可以被任意连接:3 < 5 < 7返回True。 |
|
> |
大于 |
返回x是否大于y |
5 > 3返回True。如果两个操作数都是数字,它们首先被转换为一个共同的类型。否则,它总是返回False。 |
|
<= |
小于等于 |
返回x是否小于等于y |
x = 3; y = 6; x <= y返回True。 |
|
>= |
大于等于 |
返回x是否大于等于y |
x = 4; y = 3; x >= y返回True。 |
|
== |
等于 |
比较对象是否相等 |
x = 2; y = 2; x == y返回True。x = 'str'; y = 'stR'; x == y返回False。x = 'str'; y = 'str'; x == y返回True。 |
|
!= |
不等于 |
比较两个对象是否不相等 |
x = 2; y = 3; x != y返回True。 |
|
not |
布尔“非” |
如果x为True,返回False。如果x为False,它返回True。 |
x = True; not x返回False。 |
|
and |
布尔“与” |
如果x为False,x and y返回False,否则它返回y的计算值。 |
x = False; y = True; x and y,由于x是False,返回False。在这里,Python不会计算y,因为它知道这个表达式的值肯定是False(因为x是False)。这个现象称为短路计算。 |
|
or |
布尔“或” |
如果x是True,它返回True,否则它返回y的计算值。 |
x = True; y = False; x or y返回True。短路计算在这里也适用。 |
4、基本的数据类型
数字的方法都放在int类中,而数字是类的实例化。 如上图所示。
可以通过type(a),来查看数据类型,变量的地址用id(a),来查看
int(整型)
在64位系统上,整数的位数为64位,取值范围为-2**63~2**63-1,即-9223372036854775808~9223372036854775807
1 class int(object): 2 """ 3 int(x=0) -> int or long 4 int(x, base=10) -> int or long 5 6 Convert a number or string to an integer, or return 0 if no arguments 7 are given. If x is floating point, the conversion truncates towards zero. 8 If x is outside the integer range, the function returns a long instead. 9 10 If x is not a number or if base is given, then x must be a string or 11 Unicode object representing an integer literal in the given base. The 12 literal can be preceded by '+' or '-' and be surrounded by whitespace. 13 The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to 14 interpret the base from the string as an integer literal. 15 >>> int('0b100', base=0) 16 """ 17 def bit_length(self): 18 """ 返回表示该数字的时占用的最少位数 """ 19 """ 20 int.bit_length() -> int 21 22 Number of bits necessary to represent self in binary. 23 >>> bin(37) 24 '0b100101' 25 >>> (37).bit_length() 26 """ 27 return 0 28 29 def conjugate(self, *args, **kwargs): # real signature unknown 30 """ 返回该复数的共轭复数 """ 31 """ Returns self, the complex conjugate of any int. """ 32 pass 33 34 def __abs__(self): 35 """ 返回绝对值 """ 36 """ x.__abs__() <==> abs(x) """ 37 pass 38 39 def __add__(self, y): 40 """ x.__add__(y) <==> x+y """ 41 pass 42 43 def __and__(self, y): 44 """ x.__and__(y) <==> x&y """ 45 pass 46 47 def __cmp__(self, y): 48 """ 比较两个数大小 """ 49 """ x.__cmp__(y) <==> cmp(x,y) """ 50 pass 51 52 def __coerce__(self, y): 53 """ 强制生成一个元组 """ 54 """ x.__coerce__(y) <==> coerce(x, y) """ 55 pass 56 57 def __divmod__(self, y): 58 """ 相除,得到商和余数组成的元组 """ 59 """ x.__divmod__(y) <==> divmod(x, y) """ 60 pass 61 62 def __div__(self, y): 63 """ x.__div__(y) <==> x/y """ 64 pass 65 66 def __float__(self): 67 """ 转换为浮点类型 """ 68 """ x.__float__() <==> float(x) """ 69 pass 70 71 def __floordiv__(self, y): 72 """ x.__floordiv__(y) <==> x//y """ 73 pass 74 75 def __format__(self, *args, **kwargs): # real signature unknown 76 pass 77 78 def __getattribute__(self, name): 79 """ x.__getattribute__('name') <==> x.name """ 80 pass 81 82 def __getnewargs__(self, *args, **kwargs): # real signature unknown 83 """ 内部调用 __new__方法或创建对象时传入参数使用 """ 84 pass 85 86 def __hash__(self): 87 """如果对象object为哈希表类型,返回对象object的哈希值。哈希值为整数。在字典查找中,哈希值用于快速比较字典的键。两个数值如果相等,则哈希值也相等。""" 88 """ x.__hash__() <==> hash(x) """ 89 pass 90 91 def __hex__(self): 92 """ 返回当前数的 十六进制 表示 """ 93 """ x.__hex__() <==> hex(x) """ 94 pass 95 96 def __index__(self): 97 """ 用于切片,数字无意义 """ 98 """ x[y:z] <==> x[y.__index__():z.__index__()] """ 99 pass 100 101 def __init__(self, x, base=10): # known special case of int.__init__ 102 """ 构造方法,执行 x = 123 或 x = int(10) 时,自动调用,暂时忽略 """ 103 """ 104 int(x=0) -> int or long 105 int(x, base=10) -> int or long 106 107 Convert a number or string to an integer, or return 0 if no arguments 108 are given. If x is floating point, the conversion truncates towards zero. 109 If x is outside the integer range, the function returns a long instead. 110 111 If x is not a number or if base is given, then x must be a string or 112 Unicode object representing an integer literal in the given base. The 113 literal can be preceded by '+' or '-' and be surrounded by whitespace. 114 The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to 115 interpret the base from the string as an integer literal. 116 >>> int('0b100', base=0) 117 # (copied from class doc) 118 """ 119 pass 120 121 def __int__(self): 122 """ 转换为整数 """ 123 """ x.__int__() <==> int(x) """ 124 pass 125 126 def __invert__(self): 127 """ x.__invert__() <==> ~x """ 128 pass 129 130 def __long__(self): 131 """ 转换为长整数 """ 132 """ x.__long__() <==> long(x) """ 133 pass 134 135 def __lshift__(self, y): 136 """ x.__lshift__(y) <==> x<<y """ 137 pass 138 139 def __mod__(self, y): 140 """ x.__mod__(y) <==> x%y """ 141 pass 142 143 def __mul__(self, y): 144 """ x.__mul__(y) <==> x*y """ 145 pass 146 147 def __neg__(self): 148 """ x.__neg__() <==> -x """ 149 pass 150 151 @staticmethod # known case of __new__ 152 def __new__(S, *more): 153 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 154 pass 155 156 def __nonzero__(self): 157 """ x.__nonzero__() <==> x != 0 """ 158 pass 159 160 def __oct__(self): 161 """ 返回改值的 八进制 表示 """ 162 """ x.__oct__() <==> oct(x) """ 163 pass 164 165 def __or__(self, y): 166 """ x.__or__(y) <==> x|y """ 167 pass 168 169 def __pos__(self): 170 """ x.__pos__() <==> +x """ 171 pass 172 173 def __pow__(self, y, z=None): 174 """ 幂,次方 """ 175 """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """ 176 pass 177 178 def __radd__(self, y): 179 """ x.__radd__(y) <==> y+x """ 180 pass 181 182 def __rand__(self, y): 183 """ x.__rand__(y) <==> y&x """ 184 pass 185 186 def __rdivmod__(self, y): 187 """ x.__rdivmod__(y) <==> divmod(y, x) """ 188 pass 189 190 def __rdiv__(self, y): 191 """ x.__rdiv__(y) <==> y/x """ 192 pass 193 194 def __repr__(self): 195 """转化为解释器可读取的形式 """ 196 """ x.__repr__() <==> repr(x) """ 197 pass 198 199 def __str__(self): 200 """转换为人阅读的形式,如果没有适于人阅读的解释形式的话,则返回解释器课阅读的形式""" 201 """ x.__str__() <==> str(x) """ 202 pass 203 204 def __rfloordiv__(self, y): 205 """ x.__rfloordiv__(y) <==> y//x """ 206 pass 207 208 def __rlshift__(self, y): 209 """ x.__rlshift__(y) <==> y<<x """ 210 pass 211 212 def __rmod__(self, y): 213 """ x.__rmod__(y) <==> y%x """ 214 pass 215 216 def __rmul__(self, y): 217 """ x.__rmul__(y) <==> y*x """ 218 pass 219 220 def __ror__(self, y): 221 """ x.__ror__(y) <==> y|x """ 222 pass 223 224 def __rpow__(self, x, z=None): 225 """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """ 226 pass 227 228 def __rrshift__(self, y): 229 """ x.__rrshift__(y) <==> y>>x """ 230 pass 231 232 def __rshift__(self, y): 233 """ x.__rshift__(y) <==> x>>y """ 234 pass 235 236 def __rsub__(self, y): 237 """ x.__rsub__(y) <==> y-x """ 238 pass 239 240 def __rtruediv__(self, y): 241 """ x.__rtruediv__(y) <==> y/x """ 242 pass 243 244 def __rxor__(self, y): 245 """ x.__rxor__(y) <==> y^x """ 246 pass 247 248 def __sub__(self, y): 249 """ x.__sub__(y) <==> x-y """ 250 pass 251 252 def __truediv__(self, y): 253 """ x.__truediv__(y) <==> x/y """ 254 pass 255 256 def __trunc__(self, *args, **kwargs): 257 """ 返回数值被截取为整形的值,在整形中无意义 """ 258 pass 259 260 def __xor__(self, y): 261 """ x.__xor__(y) <==> x^y """ 262 pass 263 264 denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 265 """ 分母 = 1 """ 266 """the denominator of a rational number in lowest terms""" 267 268 imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 269 """ 虚数,无意义 """ 270 """the imaginary part of a complex number""" 271 272 numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 273 """ 分子 = 数字大小 """ 274 """the numerator of a rational number in lowest terms""" 275 276 real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 277 """ 实属,无意义 """ 278 """the real part of a complex number""" 279 280 int