string.count('x'): 这将返回字符串中'x'的出现次数 string.find('x'): 这将返回字符串中字符'x'的位置 string.lower(): 这将把字符串转换为小写 string.upper(): 这将把字符串转换为大写 string.replace('a', 'b'): 这将用b替换字符串中的所有a 此外,我们可以使用len()方法获取字符串中字符的数...
Truncate the file to at most sizebytes.(文件截取) In [113]: f1.truncate(f1.tell()) #(指针所在处之后的内容全部删掉) In [115]: f1.closed #(closed是属性,判断文件是否为关闭状态) Out[115]: False In [116]: f1.encoding #(获取当前文件编码) In [117]: f1.mode #(获取当前文件打开时...
f.truncate:截取最大指定字节 注意: 文件方法read()等在读取文件时,会一并读取其行结束符 文件方法write()执行写出操作时,不会自动为其添加行结束符 6、文件对象属性 with语法 2.5开始支持with语法 用于需要打开、关闭成对的操作 可以自动关闭打开的对象 语法: with open_expr as obj: expression 代码语...
an integer (may be a long integer)."""passdeftruncate(self, size=None):#real signature unknown; restored from __doc__截断数据,仅保留指定之前数据"""truncate([size]) -> None. Truncate the file to at most
>>> outtab = "12345" #This is the string having corresponding mapping character >>> trantab = str.maketrans(intab, outtab) >>> >>> str = "this is string example...wow!!!" >>> str.translate(trantab) 'th3s 3s str3ng 2x1mpl2...w4w!!!' msg.partition('is') 输出 ('my ...
truncate to_csv bool at clip radd to_markdown value_counts first isna between_time replace sample idxmin div iloc add_suffix pipe to_sql items max rsub flags sem to_string to_excel prod fillna backfill align pct_change expanding nsmallest append attrs rmod bfill ndim rank floordiv unstack...
# string padding with left alignment print("{:5}".format("cat")) # string padding with right alignment print("{:>5}".format("cat")) # string padding with center alignment print("{:^5}".format("cat")) # string padding with center alignment # and '*' padding character print("{:...
dirp) return NULL; /* Convert directory name to wide-character string */ wchar_t wname[PATH_MAX + 1]; size_t n; int error = mbstowcs_s(&n, wname, PATH_MAX + 1, dirname, PATH_MAX + 1); if (error) goto exit_failure; /* Open directory stream using wide-character name */ ...
(文件最开始) f.seek(0) #1 #如果不是rb模式打开文件,就会报错io.UnsupportedOperation: can't do nonzero end-relative seeks f.truncate(20) #用读写模式打开rb+,truncate表示只保留前20个字节(字符、字母),如果是只读模式,会报错 # Truncate the file to at most size bytes and return the truncated ...
Padding is done using the specified fill character (default is a space). """ return "" def rsplit(self, sep=None, maxsplit=-1): """ S.rsplit(sep=None, maxsplit=-1) -> list of strings Return a list of the words in S, using sep as the delimiter string, starting at the ...