打印DataFrame:如何格式化日期索引的显示方式?

时间:2013-09-20 21:54:58

标签: python-2.7 pandas

当输出带有日期索引的DataFrame时,pandas正在砍掉小时,分钟,秒:

print df

--output:--
             Open   High    Low  Close   Volume  Adj Close
1990-01-02  35.25  37.50  35.00  37.25  6555600       8.70
1990-01-03  38.00  38.00  37.50  37.50  7444400       8.76
1990-01-04  38.25  38.75  37.25  37.63  7928800       8.79
1990-01-05  37.75  38.25  37.00  37.75  4406400       8.82
1990-01-08  37.50  38.00  37.00  38.00  3643200       8.88

以下是DataFrame的创建方式:

data.txt(制表符分隔):

1990-01-02 00:00:00 35.25   37.50   35.00   37.25   6555600 8.70
1990-01-03 00:00:00 38.00   38.00   37.50   37.50   7444400 8.76
1990-01-04 00:00:00 38.25   38.75   37.25   37.63   7928800 8.79
1990-01-05 00:00:00 37.75   38.25   37.00   37.75   4406400 8.82
1990-01-08 00:00:00 37.50   38.00   37.00   38.00   3643200 8.88

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.dates as md
import datetime as dt


    df = pd.read_table(
        'data.txt',
        names=[
            'Open',
            'High',
            'Low',
            'Close',
            'Volume',
            'Adj Close',
        ],
        index_col = 0,
        parse_dates=True,
        date_parser=lambda s: dt.datetime.strptime(s, '%Y-%m-%d %H:%M:%S'),

    )

如果data.txt中的其中一个日期的小时,分​​钟,秒等非零值,例如:

1990-01-02 00:00:00 35.25   37.50   35.00   37.25   6555600 8.70
1990-01-03 00:00:00 38.00   38.00   37.50   37.50   7444400 8.76
1990-01-04 00:00:01 38.25   38.75   37.25   37.63   7928800 8.79
1990-01-05 00:00:00 37.75   38.25   37.00   37.75   4406400 8.82
1990-01-08 00:00:00 37.50   38.00   37.00   38.00   3643200 8.88

然后输出正确':

                      Open   High    Low  Close   Volume  Adj Close
1990-01-02 00:00:00  35.25  37.50  35.00  37.25  6555600       8.70
1990-01-03 00:00:00  38.00  38.00  37.50  37.50  7444400       8.76
1990-01-04 00:00:01  38.25  38.75  37.25  37.63  7928800       8.79
1990-01-05 00:00:00  37.75  38.25  37.00  37.75  4406400       8.82
1990-01-08 00:00:00  37.50  38.00  37.00  38.00  3643200       8.88

写作:

print df.to_string()

没有帮助。而且我没有看到格式化日期的打印选项:

pd.describe_option()

--output:--


display.chop_threshold: [default: None] [currently: None]
: float or None
        if set to a float value, all float values smaller then the given threshold
        will be displayed as exactly 0 by repr and friends.
display.colheader_justify: [default: right] [currently: right]
: 'left'/'right'
        Controls the justification of column headers. used by DataFrameFormatter.
display.column_space: [default: 12] [currently: 12]No description available.

display.date_dayfirst: [default: False] [currently: False]
: boolean
        When True, prints and parses dates with the day first, eg 20/01/2005
display.date_yearfirst: [default: False] [currently: False]
: boolean
        When True, prints and parses dates with the year first, eg 2005/01/20
display.encoding: [default: UTF-8] [currently: UTF-8]
: str/unicode
        Defaults to the detected encoding of the console.
        Specifies the encoding to be used for strings returned by to_string,
        these are generally strings meant to be displayed on the console.
display.expand_frame_repr: [default: True] [currently: True]
: boolean
        Whether to print out the full DataFrame repr for wide DataFrames
        across multiple lines, `max_columns` is still respected, but the output will
        wrap-around across multiple "pages" if it's width exceeds `display.width`.
display.float_format: [default: None] [currently: None]
: callable
        The callable should accept a floating point number and return
        a string with the desired format of the number. This is used
        in some places like SeriesFormatter.
        See core.format.EngFormatter for an example.
display.height: [default: 60] [currently: 60]
: int
        Deprecated.
    (Deprecated, use `display.height` instead.)

display.line_width: [default: 80] [currently: 80]
: int
        Deprecated.
    (Deprecated, use `display.width` instead.)

display.max_columns: [default: 20] [currently: 20]
: int
        max_rows and max_columns are used in __repr__() methods to decide if
        to_string() or info() is used to render an object to a string.  In case
        python/IPython is running in a terminal this can be set to 0 and pandas
        will correctly auto-detect the width the terminal and swap to a smaller
        format in case all columns would not fit vertically. The IPython notebook,
        IPython qtconsole, or IDLE do not run in a terminal and hence it is not
        possible to do correct auto-detection.
        'None' value means unlimited.
display.max_colwidth: [default: 50] [currently: 50]
: int
        The maximum width in characters of a column in the repr of
        a pandas data structure. When the column overflows, a "..."
        placeholder is embedded in the output.
display.max_info_columns: [default: 100] [currently: 100]
: int
        max_info_columns is used in DataFrame.info method to decide if
        per column information will be printed.
display.max_info_rows: [default: 1690785] [currently: 1690785]
: int or None
        max_info_rows is the maximum number of rows for which a frame will
        perform a null check on its columns when repr'ing To a console.
        The default is 1,000,000 rows. So, if a DataFrame has more
        1,000,000 rows there will be no null check performed on the
        columns and thus the representation will take much less time to
        display in an interactive session. A value of None means always
        perform a null check when repr'ing.
display.max_rows: [default: 60] [currently: 60]
: int
        This sets the maximum number of rows pandas should output when printing
        out various output. For example, this value determines whether the repr()
        for a dataframe prints out fully or just a summary repr.
        'None' value means unlimited.
display.max_seq_items: [default: None] [currently: None]
: int or None

        when pretty-printing a long sequence, no more then `max_seq_items`
        will be printed. If items are ommitted, they will be denoted by the addition
        of "..." to the resulting string.

        If set to None, the number of items to be printed is unlimited.
display.mpl_style: [default: None] [currently: None]
: bool

        Setting this to 'default' will modify the rcParams used by matplotlib
        to give plots a more pleasing visual style by default.
        Setting this to None/False restores the values to their initial value.
display.multi_sparse: [default: True] [currently: True]
: boolean
        "sparsify" MultiIndex display (don't display repeated
        elements in outer levels within groups)
display.notebook_repr_html: [default: True] [currently: True]
: boolean
        When True, IPython notebook will use html representation for
        pandas objects (if it is available).
display.pprint_nest_depth: [default: 3] [currently: 3]
: int
        Controls the number of nested levels to process when pretty-printing
display.precision: [default: 7] [currently: 7]
: int
        Floating point output precision (number of significant digits). This is
        only a suggestion
display.width: [default: 80] [currently: 80]
: int
        Width of the display in characters. In case python/IPython is running in
        a terminal this can be set to None and pandas will correctly auto-detect the
        width.
        Note that the IPython notebook, IPython qtconsole, or IDLE do not run in a
        terminal and hence it is not possible to correctly detect the width.
mode.sim_interactive: [default: False] [currently: False]
: boolean
        Whether to simulate interactive mode for purposes of testing
mode.use_inf_as_null: [default: False] [currently: False]
: boolean
        True means treat None, NaN, INF, -INF as null (old way),
        False means None and NaN are null, but INF, -INF are not null
        (new way).

1 个答案:

答案 0 :(得分:0)

为什么不重置索引并在没有它的情况下进行打印:

import pandas.util.testing as tm
df = tm.makeTimeDataFrame()
print(df.reset_index().to_string(index=False))

给出:

              index      A      B      C      D
2000-01-03 00:00:00 -1.377  1.601 -0.066  0.138
2000-01-04 00:00:00  0.106  0.240 -1.213 -0.609
2000-01-05 00:00:00 -0.382  0.699  1.183  0.007
2000-01-06 00:00:00  0.873 -0.928  0.041  0.021
2000-01-07 00:00:00 -0.585  0.009 -0.206  0.672
2000-01-10 00:00:00 -0.421 -0.813 -1.150 -0.093
2000-01-11 00:00:00 -2.314 -0.217 -1.206 -1.618
2000-01-12 00:00:00 -0.771 -1.206  2.194  0.068
2000-01-13 00:00:00  0.430  0.937  1.680 -0.461
2000-01-14 00:00:00 -0.294 -0.593 -0.130 -0.053
2000-01-17 00:00:00 -1.261 -0.317 -0.944 -0.596
2000-01-18 00:00:00 -0.821 -0.768  0.163 -1.301
2000-01-19 00:00:00 -1.194  1.346 -0.302  1.049
2000-01-20 00:00:00  1.213 -0.609  0.893  0.545
2000-01-21 00:00:00 -1.956  0.614 -0.712 -0.828
2000-01-24 00:00:00 -0.355 -1.103  0.459 -0.655
2000-01-25 00:00:00 -0.569  0.250 -0.434  0.045
2000-01-26 00:00:00 -0.532  0.202  0.140  1.055
2000-01-27 00:00:00  0.760 -0.289 -0.372 -0.632
2000-01-28 00:00:00  0.320  1.704  0.339 -0.822
2000-01-31 00:00:00 -2.353  0.988  0.066  2.685
2000-02-01 00:00:00 -0.130  0.064  0.975  0.708
2000-02-02 00:00:00  0.723 -0.332  1.053  0.386
2000-02-03 00:00:00  1.499  1.682  1.147  1.275
2000-02-04 00:00:00 -1.837 -0.475 -0.987 -0.592
2000-02-07 00:00:00  0.728 -0.055  1.683  1.994
2000-02-08 00:00:00 -0.037 -0.454  0.154 -1.205
2000-02-09 00:00:00 -0.680 -1.523  1.382  0.700
2000-02-10 00:00:00  0.780 -0.155  0.598 -0.419
2000-02-11 00:00:00  1.021 -0.743 -0.210  0.491