[Python] Output data from all columns in a dataframe in pandas


Answers

Use:

pandas.set_option('display.max_columns', 7)

This will force Pandas to display the 7 columns you have. Or more generally:

pandas.set_option('display.max_columns', None)

which will force it to display any number of columns.

Explanation: the default for max_columns is 0, which tells Pandas to display the table only if all the columns can be squeezed into the width of your console.

Question

I have a csv file with the name params.csv. I opened up ipython qtconsole and created a pandas dataframe using:

import pandas
paramdata = pandas.read_csv('params.csv', names=paramnames)

where, paramnames is a python list of string objects. Example of paramnames (the length of actual list is 22):

paramnames = ["id",
"fc",
"mc",
"markup",
"asplevel",
"aspreview",
"reviewpd"]

At the ipython prompt if I type paramdata and press enter then I do not get the dataframe with columns and values as shown in examples on Pandas website. Instead, I get information about the dataframe. I get:

In[35]: paramdata
Out[35]: 
<class 'pandas.core.frame.DataFrame'>
Int64Index: 59 entries, 0 to 58
Data columns:
id                    59  non-null values
fc                    59  non-null values
mc                    59  non-null values
markup                59  non-null values
asplevel              59  non-null values
aspreview             59  non-null values
reviewpd              59  non-null values

If I type paramdata['mc'] then I do get the values as expected for the mc column. I have two questions:

(1) In the examples on the pandas website (see, for example, the output of df here: http://pandas.sourceforge.net/indexing.html#additional-column-access) typing the name of the dataframe gives the actual data. Why am I getting information about the dataframe as shown above instead of the actual data? Do I need to set some output options somewhere?

(2) How do I output all columns in the dataframe to the screen without having to type their names, i.e., without having to type something like paramdata[['id','fc','mc']].

I am using pandas version 0.8.

Thank you.




Python pandas, how to widen output display to see more columns?

As @bmu mentioned, pandas auto detects (by default) the size of the display area, a summary view will be used when an object repr does not fit on the display. You mentioned resizing the IDLE window, to no effect. If you do print df.describe().to_string() does it fit on the IDLE window?

The terminal size is determined by pandas.util.terminal.get_terminal_size(), this returns a tuple containing the (width, height) of the display. Does the output match the size of your IDLE window? There might be an issue (there was one before when running a terminal in emacs).

Note that it is possible to bypass the autodetect, pandas.set_printoptions(max_rows=200, max_columns=10) will never switch to summary view if number of rows, columns does not exceed the given limits.


Update: Pandas 0.11.0 onwards

pandas.set_printoptions(...) is depracted. Instead, use pandas.set_option. Like:

import pandas as pd
pd.set_option('display.height', 1000)
pd.set_option('display.max_rows', 500)
pd.set_option('display.max_columns', 500)
pd.set_option('display.width', 1000)

Here is the help:

set_option(pat,value) - Sets the value of the specified option

Available options:
display.[chop_threshold, colheader_justify, column_space, date_dayfirst,
         date_yearfirst, encoding, expand_frame_repr, float_format, height,
         line_width, max_columns, max_colwidth, max_info_columns, max_info_rows,
         max_rows, max_seq_items, mpl_style, multi_sparse, notebook_repr_html,
         pprint_nest_depth, precision, width]
mode.[sim_interactive, use_inf_as_null]

Parameters
----------
pat - str/regexp which should match a single option.

Note: partial matches are supported for convenience, but unless you use the
full option name (e.g. x.y.z.option_name), your code may break in future
versions if new options with similar names are introduced.

value - new value of option.

Returns
-------
None

Raises
------
KeyError if no such option exists

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: 1000]
: int
        Deprecated.
        (Deprecated, use `display.height` instead.)

display.line_width: [default: 80] [currently: 1000]
: int
        Deprecated.
        (Deprecated, use `display.width` instead.)

display.max_columns: [default: 20] [currently: 500]
: 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: 500]
: 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: 1000]
: 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).
Call def:   pd.set_option(self, *args, **kwds)



In ipython, I use this to print a part of the dataframe that works quite well (prints the first 100 rows):

print paramdata.head(100).to_string()



How to remove ellipsis from a row in a Python Pandas series or data frame, shown when long lines/wide columns are truncated?

pandas is truncating the output, you can change this:

In [4]:

data = pd.Series(['a', 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'aaaaaaaaaaaaaaaa', 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'])

pd.set_option('display.max_colwidth',1000)

data

Out[4]:

0                                                                         a
1    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2         aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
3                                                          aaaaaaaaaaaaaaaa
4        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
dtype: object

also see related: Output data from all columns in a dataframe in pandas and Output data from all columns in a dataframe in pandas

By the way if you are using IPython then if you do a docstring lookup (by pressing tab) then you will see the current values and the default values (the default is 50 characters).

For Pandas versions older than 0.10 use

pd.set_printoptions(max_colwidth, 1000)

See related: Python pandas, how to widen output display to see more columns?




Is this what you meant to do ?

In [7]: x =  pd.DataFrame({'one' : ['one', 'two', 'This is very long string very long string very long string veryvery long string']})

In [8]: x
Out[8]: 
                                                 one
0                                                one
1                                                two
2  This is very long string very long string very...

In [9]: x['one'][2]
Out[9]: 'This is very long string very long string very long string veryvery long string'



If you want to set options temporarily to display one large DataFrame, you can use option_context:

with pd.option_context('display.max_rows', -1, 'display.max_columns', 5):
    print df

Option values are restored automatically when you exit the with block.