raise ValueError("time data %r does not match format %r" % ValueError: time data '202b-10-30' does not match format '%Y-%m-%d' 日期= None 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 堆栈信息从上往下为程序执行过程中函数(或方法)的调用顺序,其中的
7 8 Public module variables: 9 10 whitespace -- a string containing all characters considered whitespace 11 lowercase -- a string containing all characters considered lowercase letters 12 uppercase -- a string containing all characters considered uppercase letters 13 letters -- a string containing a...
# SyntaxError: invalid decimal literal s = 0 for i in range(1, 6): # 此处中文逗号要改成英文逗号 s = s + i print( s) 下面这个简单的Python程序(来自https://bugfree.cc/),可以用来检查字符串中是否包含非英文符号。 ''' 找出字符串中的非英文字符, 用^指出。 ''' def find_chinese_char(...
In a raw string literal (as indicated by the prefix r), the backslashes pass themselves as is along with the behavior of escaping the following character. >>> r'wt\"f' == 'wt\\"f' True >>> print(repr(r'wt\"f')) 'wt\\"f' >>> print("\n") >>> print(r"\\n") '\\n...
Notice that we can use an arbitrary expression in the square brackets, not just a hardcoded number literal—anywhere that Python expects a value, we can use a literal, a variable, or any expression. Python’s syntax is completely general this way. In addition to simple positional indexing, ...
'stRINg lEArn ' >>> >>> str.rjust(20) #str右对齐 ' stRINg lEArn' >>> >>> str.zfill(20) #str右对齐,左边填充0 '00000000stRINg lEArn' 大小写转换 >>> str='stRINg lEArn' >>> >>> str.upper() #转大写 'STRING LEARN' >>> ...
[-T:+\d]{25}matches the time stamp, which you explored in the last section. Since you won’t be using the time stamp in the final transcript, it’s not captured with brackets. :matches a literal colon. The colon is used as a separator between the message metadata and the message it...
substring not found >>> str.index("n") #同find类似,返回第一次匹配的索引值 4 >>> str.rindex("n") #返回最后一次匹配的索引值 11 >>> str.count('a') #字符串中匹配的次数 0 >>> str.count('n') #同上 2 >>> str.replace('EAR','ear') #匹配替换 'string learn' >>> str.replace...
In this quick example, you use the % operator to interpolate the value of your name variable into a string literal. The interpolation operator takes two operands:A string literal containing one or more conversion specifiers The object or objects that you’re interpolating into the string literal...
Note that “bar” in a template expression like {{ foo.bar }} will be interpreted as a literal string and not using the value of the variable “bar”, if one exists in the template context. The template system uses the first lookup type that works. It’s short-circuit logic. Here ar...