Python||pd.read_csv()函数中parse_dates()参数详解
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read_csv()参数列表，官方文档
pandas.read_csv(filepath_or_buffer, sep=', ', delimiter=None, header='infer', names=None, index_col=None, usecols=None, squeeze=False, prefix=None, mangle_dupe_cols=True, dtype=None, engine=None, converters=None, true_values=None, false_values=None, skipinitialspace=False, skiprows=None, nrows=None, na_values=None, keep_default_na=True, na_filter=True, verbose=False, skip_blank_lines=True, parse_dates=False, infer_datetime_format=False, keep_date_col=False, date_parser=None, dayfirst=False, iterator=False, chunksize=None, compression='infer', thousands=None, decimal=b'.', lineterminator=None, quotechar='"', quoting=0, escapechar=None, comment=None, encoding=None, dialect=None, tupleize_cols=None, error_bad_lines=True, warn_bad_lines=True, skipfooter=0, doublequote=True, delim_whitespace=False, low_memory=True, memory_map=False, float_precision=None)
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parse_dates()参数详解
parse_dates : boolean or list of ints or names or list of lists or dict, default False
- boolean. If True -> try parsing the index.
- list of ints or names. e.g. If [1, 2, 3] -> try parsing columns 1, 2, 3 each as a separate date column.
- list of lists. e.g. If [[1, 3]] -> combine columns 1 and 3 and parse as a single date column.
- dict, e.g. {‘foo’ : [1, 3]} -> parse columns 1, 3 as date and call result ‘foo’
If a column or index contains an unparseable date, the entire column or index will be returned unaltered as an object data type. For non-standard datetime parsing, use
pd.to_datetimeafterpd.read_csvNote: A fast-path exists for iso8601-formatted dates.
翻译后：
- boolean. True -> 解析索引
- list of ints or names. e.g. If [1, 2, 3] -> 解析1,2,3列的值作为独立的日期列；
- list of lists. e.g. If [[1, 3]] -> 合并1,3列作为一个日期列使用
- dict, e.g. {‘foo’ : [1, 3]} -> 将1,3列合并，并给合并后的列起名为"foo"
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参考
漫步者
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2018-11-21 14:10:50写于德州乐陵
上次写这个文件时，刚接触Python，今天一看这个文章，啥也没解释嘛？
简单来讲，这个参数的意思就是将哪一列解析为时间索引。
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2019-03-27 13:07:25写于浦东图书馆