2.字面常量(不会改变) 可以直接以字面的意义使用它们: 如:6,2.24,3.45e-3,"this is a string"
Strings can beconcatenatedto build longer strings using the plus sign and also they can bemultipliedby a number, which results in the continuous repetition of the string as many times as the number indicates. Also, if we want to find out thelengthof the string, we simply have to use thelen...
last): File "<stdin>", line 1, in <module> TypeError: 'set' object does not support indexing、 与集合有关的方法和函数 add() add()用来一组集合里添加新元素其返回值依然是集合,举例如下: >>> vendors.add('Huawei') >>> vendorsset
for variable in string: statement statement etc. 例子: >>> name = 'Juliet' >>> for ch in name: print ch J u l i e 例2: # This program counts the number times # the letter T appears in a string. def main(): count = 0 my_string = raw_input('Enter a sentence: ') for ch...
batch=200forxinrange(len(order_nos)/batch+1):#dosomething 其中,order_nos是订单列表,而在Python 3环境下运行时会提“TypeError:'float' object cannot be interpreted as an integer”错误,意思是float类型不能解释为int类型。这是因为在Python 3中,int和long统一为int类型,int 表示任何精度的整数。在以前的...
Syntax of String data type in Python string_variable = 'Hello, world!' Example of string data type in Python my_string = "This is a string." print(my_string) print(type(my_string)) Output This is a string.; Explanation In this example, the variable my_string is assigned the value ...
也可以是其他的，但是后面必须与之对称）（2） Long StringWhen the string variable is too long, we can add a backslash at the end of the line to indicate continuation. Or the first three double quotes, followed by the last three double quotes (echoing before and after, paired in pairs, ...
You can get the data type of a variable with thetype()function. Example x =5 y ="John" print(type(x)) print(type(y)) Try it Yourself » You will learn more aboutdata typesandcastinglater in this tutorial. Single or Double Quotes?
names=["variable3","variable4"]values=[30,40]forname,valueinzip(names,values):exec(name+" = "+str(value))print(variable3)# 输出:30print(variable4)# 输出:40 1. 2. 3. 4. 5. 6. 7. 8. 在上面的代码中,我们使用了一个for循环来遍历names和values列表,并使用exec()函数将变量名和对应的...
ValueError: Invalid placeholder in string: line 1, col 27 >>> s = Template("hello, I am ${first_name}.${last_name}") # 更换为合法的变量名后, 正常 >>> d['last_name']="digoal" >>> s.substitute(d) 'hello, I am zhou.digoal' ...