复制 print(sum(2,5)) # 7 # print(sum('hello', 2)) # TypeError: can only concatenate str (not "int") to str # print(sum(3,'world')) # TypeError: unsupported operand type(s) for +: 'int' and 'str' print(sum('hello', 'world')) # helloworld1.2.3.4.用于高级类型提示的typ...
Go ahead and create a new Canvas instance for the file hello.pdf: Python >>> canvas = Canvas("hello.pdf") You now have a Canvas instance that you’ve assigned to the variable name canvas and that’s associated with a file in your current working directory called hello.pdf. The ...
b ="very good"print(a.strip() + b)#Hello, World!very goodprint(a.strip() +" And it's "+ b)#Hello, World! And it's very goodage =36txt ="My name is Bill, I am "+ ageprint(txt)#类型不同报错#TypeError: can only concatenate str (not "int") to str 使用format() 方法组合...
每个模块都有一个__name__特殊变量(记住,Python 使用双下划线表示特殊变量,比如类的__init__方法),它指定了模块在导入时的名称。当模块直接用python module.py执行时,它不会被导入,所以__name__会被任意设置为"__main__"字符串。制定一个规则,将所有脚本都包裹在if __name__ == "__main__":测试中,...
read() FileNotFoundError: [Errno 2] No such file or directory: 'alice.txt' #alice filename='alice.txt' try: with open (filename) as f_obj: contents = f_obj.read() except FileNotFoundError: msg="sorry,the file"+filename+"does not found" print(msg) ##FileNotFoundError sorry,...
参数某个环境:conda remove --name your_env_name --all 2.常用的模块 2.1 numpy模块: (1)矩阵的拼接和分割,奇偶项分割数据 # 产生5*2的矩阵数据 data1=np.arange(0,10) data1=data1.reshape([5,2]) # 矩阵拼接 y=np.concatenate([data1,data2],0) ...
Using a context manager closes the iterator and frees up acquired resources automatically after the iterator has been exhausted. The result is a print out of the filenames in my_directory/ just like you saw in the os.listdir() example:Shell sub_dir_c file1.py sub_dir_b file3.txt ...
(config.IMDB_DATA, directory, sentiment) for review_file in os.listdir(path): with open(os.path.join(path, review_file), 'r', encoding= 'utf-8') as input_file: review = input_file.read() df = df.append([[utils.strip_html_tags(review), labels[sentiment]]], ignore_index=True) ...
# print(sum('hello', 2)) # TypeError: can only concatenate str (not "int") to str # print(sum(3,'world')) # TypeError: unsupported operand type(s) for +: 'int' and 'str' print(sum('hello', 'world')) # helloworld 用于高级类型提示的typing库 ...
Once imported, you can access various functions and attributes provided by the.pathmodule. Navigating directories One of the key functionalities of the.pathmodule is navigating directories. You can use theos.path.join()function to concatenate multiple path components and create a valid file path. This...