运算时数据类型不匹配,此处错误消息提示:尝试用字符串除以整数。 a = input() # input函数从标准输入读取字符串。 print(a / 10) 如何修改:可以将字符串转换成int,比如 a = int(input()) 13. TypeError: 'NoneType' object is not subscriptable 试图访问一个空对象的某个下标数值。 a = [3, 2, 1, ...
lower() if mode in ['encrypt', 'e', 'decrypt', 'd']: return mode else: print('Enter either "encrypt" or "e" or "decrypt" or "d".') def getMessage(): print('Enter your message:') return input() def getKey(): key = 0 while True: print('Enter the key number (1-%s)'...
x=int(raw_input(Pleaseenteraninteger:)) ifx0: ...x=0 ...printNegativechangedtozero ...elifx==0: ...printZero ...elifx==1: ...printSingle ...else: ...printMore ... 可能会有0或很多个elif部分,else是可选的。关键字“elif”是 “elseif”的缩写,这个可以有效避免过深的缩进。if.....
So selecting a single character from a string returns a single-character string. 3 --0-- 5 == 8 and --5 == 5 are both semantically correct statements and evaluate to True. Given that a is a number, ++a and --a are both valid Python statements but don't behave the same way as...
Python raw string treats backslash () as a literal character. This is useful when we want to have a string that contains backslash and don't want it to be treated as an escape character.Unicode and ASCII stringsUnicode is international standard where a mapping of individual characters and a ...
In Python, strings can be enclosed in a single quote character ('), a double quote character ("), or what’s known as triple quotes ("""or'''). As mentioned earlier, triple quotes around strings are known asdocstrings, because they are mainly used to document a function’s purpose (...
To find out what any BIF does—like input(), for example—type help(input) at the shell for a description of the BIFs function. Q: Q: Why so many BIFs? A: A: Why not? Because Python comes with lots of built-in functionality, it can mean less code for you to write. This ...
To avoid depending on X, the Linux parts reads raw device files (/dev/input/input*) but this requires root. 为了避免依赖X,Linux部分读取原始设备文件(/dev/input/input*),但需要root。 Other applications, such as some games, may register hooks that swallow all key events. In this casekeyboard...
(''' <input> <file-name>$filePath</file-name> <delete-type>$deleteType</delete-type> </input> ''') req_data = req_template.substitute(filePath=file_path, deleteType="unreserved") ret, _, _ = ops_conn.create(uri, req_data) if ops_return_result(ret): logging.error('Failed ...
sometimes looks different from the input (the enclosing quotation marks could change), the two strings are equivalent. The string is enclosed in double quotation marks if the string contains a single quotation mark and no double quotation marks. Otherwise, it’s enclosed in single quotation marks...