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.. currentmodule:: pandas

.. ipython:: python
   :suppress:

   import pandas as pd
   import numpy as np
   np.random.seed(123456)

Options and Settings

Overview

pandas has an options system that lets you customize some aspects of it's behaviour, display-related options being those the user is most likely to adjust.

Options have a full "dotted-style", case-insensitive name (e.g. display.max_rows), You can get/set options directly as attributes of the top-level options attribute:

.. ipython:: python

   import pandas as pd
   pd.options.display.max_rows
   pd.options.display.max_rows = 999
   pd.options.display.max_rows

There is also an API composed of 5 relevant functions, available directly from the pandas namespace, and they are:

Note: developers can check out pandas/core/config.py for more info.

All of the functions above accept a regexp pattern (re.search style) as an argument, and so passing in a substring will work - as long as it is unambiguous :

.. ipython:: python

   pd.get_option("display.max_rows")
   pd.set_option("display.max_rows",101)
   pd.get_option("display.max_rows")
   pd.set_option("max_r",102)
   pd.get_option("display.max_rows")


The following will not work because it matches multiple option names, e.g. display.max_colwidth, display.max_rows, display.max_columns:

.. ipython:: python
   :okexcept:

   try:
       pd.get_option("column")
   except KeyError as e:
       print(e)


Note: Using this form of shorthand may cause your code to break if new options with similar names are added in future versions.

You can get a list of available options and their descriptions with describe_option. When called with no argument describe_option will print out the descriptions for all available options.

.. ipython:: python
   :suppress:

   pd.reset_option("all")

Getting and Setting Options

As described above, get_option() and set_option() are available from the pandas namespace. To change an option, call set_option('option regex', new_value)

.. ipython:: python

   pd.get_option('mode.sim_interactive')
   pd.set_option('mode.sim_interactive', True)
   pd.get_option('mode.sim_interactive')

Note: that the option 'mode.sim_interactive' is mostly used for debugging purposes.

All options also have a default value, and you can use reset_option to do just that:

.. ipython:: python
   :suppress:

   pd.reset_option("display.max_rows")

.. ipython:: python

   pd.get_option("display.max_rows")
   pd.set_option("display.max_rows",999)
   pd.get_option("display.max_rows")
   pd.reset_option("display.max_rows")
   pd.get_option("display.max_rows")


It's also possible to reset multiple options at once (using a regex):

.. ipython:: python

   pd.reset_option("^display")


option_context context manager has been exposed through the top-level API, allowing you to execute code with given option values. Option values are restored automatically when you exit the with block:

.. ipython:: python

   with pd.option_context("display.max_rows",10,"display.max_columns", 5):
        print(pd.get_option("display.max_rows"))
        print(pd.get_option("display.max_columns"))
   print(pd.get_option("display.max_rows"))
   print(pd.get_option("display.max_columns"))


Setting Startup Options in python/ipython Environment

Using startup scripts for the python/ipython environment to import pandas and set options makes working with pandas more efficient. To do this, create a .py or .ipy script in the startup directory of the desired profile. An example where the startup folder is in a default ipython profile can be found at:

$IPYTHONDIR/profile_default/startup

More information can be found in the ipython documentation. An example startup script for pandas is displayed below:

import pandas as pd
pd.set_option('display.max_rows', 999)
pd.set_option('precision', 5)

Frequently Used Options

The following is a walkthrough of the more frequently used display options.

display.max_rows and display.max_columns sets the maximum number of rows and columns displayed when a frame is pretty-printed. Truncated lines are replaced by an ellipsis.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(7,2))
   pd.set_option('max_rows', 7)
   df
   pd.set_option('max_rows', 5)
   df
   pd.reset_option('max_rows')

display.expand_frame_repr allows for the the representation of dataframes to stretch across pages, wrapped over the full column vs row-wise.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(5,10))
   pd.set_option('expand_frame_repr', True)
   df
   pd.set_option('expand_frame_repr', False)
   df
   pd.reset_option('expand_frame_repr')

display.large_repr lets you select whether to display dataframes that exceed max_columns or max_rows as a truncated frame, or as a summary.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(10,10))
   pd.set_option('max_rows', 5)
   pd.set_option('large_repr', 'truncate')
   df
   pd.set_option('large_repr', 'info')
   df
   pd.reset_option('large_repr')
   pd.reset_option('max_rows')

display.max_columnwidth sets the maximum width of columns. Cells of this length or longer will be truncated with an ellipsis.

.. ipython:: python

   df=pd.DataFrame(np.array([['foo', 'bar', 'bim', 'uncomfortably long string'],
                        ['horse', 'cow', 'banana', 'apple']]))
   pd.set_option('max_colwidth',40)
   df
   pd.set_option('max_colwidth', 6)
   df
   pd.reset_option('max_colwidth')

display.max_info_columns sets a threshold for when by-column info will be given.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(10,10))
   pd.set_option('max_info_columns', 11)
   df.info()
   pd.set_option('max_info_columns', 5)
   df.info()
   pd.reset_option('max_info_columns')

display.max_info_rows: df.info() will usually show null-counts for each column. For large frames this can be quite slow. max_info_rows and max_info_cols limit this null check only to frames with smaller dimensions then specified. Note that you can specify the option df.info(null_counts=True) to override on showing a particular frame.

.. ipython:: python

   df=pd.DataFrame(np.random.choice([0,1,np.nan],size=(10,10)))
   df
   pd.set_option('max_info_rows', 11)
   df.info()
   pd.set_option('max_info_rows', 5)
   df.info()
   pd.reset_option('max_info_rows')

display.precision sets the output display precision. This is only a suggestion.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(5,5))
   pd.set_option('precision',7)
   df
   pd.set_option('precision',4)
   df

display.chop_threshold sets at what level pandas rounds to zero when it displays a Series of DataFrame. Note, this does not effect the precision at which the number is stored.

.. ipython:: python

   df=pd.DataFrame(np.random.randn(6,6))
   pd.set_option('chop_threshold', 0)
   df
   pd.set_option('chop_threshold', .5)
   df
   pd.reset_option('chop_threshold')

display.colheader_justify controls the justification of the headers. Options are 'right', and 'left'.

.. ipython:: python

   df=pd.DataFrame(np.array([np.random.randn(6), np.random.randint(1,9,6)*.1, np.zeros(6)]).T, columns=['A', 'B', 'C'], dtype='float')
   pd.set_option('colheader_justify', 'right')
   df
   pd.set_option('colheader_justify', 'left')
   df
   pd.reset_option('colheader_justify')



List of Options

Option Default Function
display.chop_threshold 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 right Controls the justification of column headers. used by DataFrameFormatter.
display.column_space 12 No description available.
display.date_dayfirst False When True, prints and parses dates with the day first, eg 20/01/2005
display.date_yearfirst False When True, prints and parses dates with the year first, eg 2005/01/20
display.encoding UTF-8 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 True 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 None 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 60 Deprecated. Use display.max_rows instead.
display.large_repr truncate For DataFrames exceeding max_rows/max_cols, the repr (and HTML repr) can show a truncated table (the default from 0.13), or switch to the view from df.info() (the behaviour in earlier versions of pandas). allowable settings, ['truncate', 'info']
display.line_width 80 Deprecated. Use display.width instead.
display.max_columns 20 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 50 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 100 max_info_columns is used in DataFrame.info method to decide if per column information will be printed.
display.max_info_rows 1690785 df.info() will usually show null-counts for each column. For large frames this can be quite slow. max_info_rows and max_info_cols limit this null check only to frames with smaller dimensions then specified.
display.max_rows 60 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 100 when pretty-printing a long sequence, no more then max_seq_items will be printed. If items are omitted, 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.memory_usage True This specifies if the memory usage of a DataFrame should be displayed when the df.info() method is invoked.
display.mpl_style None 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 True "Sparsify" MultiIndex display (don't display repeated elements in outer levels within groups)
display.notebook_repr_html True When True, IPython notebook will use html representation for pandas objects (if it is available).
display.pprint_nest_depth 3 Controls the number of nested levels to process when pretty-printing
display.precision 7 Floating point output precision (number of significant digits). This is only a suggestion
display.show_dimensions truncate Whether to print out dimensions at the end of DataFrame repr. If 'truncate' is specified, only print out the dimensions if the frame is truncated (e.g. not display all rows and/or columns)
display.width 80 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.
io.excel.xls.writer xlwt The default Excel writer engine for 'xls' files.
io.excel.xlsm.writer openpyxl The default Excel writer engine for 'xlsm' files. Available options: 'openpyxl' (the default).
io.excel.xlsx.writer openpyxl The default Excel writer engine for 'xlsx' files.
io.hdf.default_format None default format writing format, if None, then put will default to 'fixed' and append will default to 'table'
io.hdf.dropna_table True drop ALL nan rows when appending to a table
mode.chained_assignment warn Raise an exception, warn, or no action if trying to use chained assignment, The default is warn
mode.sim_interactive False Whether to simulate interactive mode for purposes of testing
mode.use_inf_as_null False 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).

Number Formatting

pandas also allow you to set how numbers are displayed in the console. This option is not set through the set_options API.

Use the set_eng_float_format function to alter the floating-point formatting of pandas objects to produce a particular format.

For instance:

.. ipython:: python

   import numpy as np

   pd.set_eng_float_format(accuracy=3, use_eng_prefix=True)
   s = pd.Series(np.random.randn(5), index=['a', 'b', 'c', 'd', 'e'])
   s/1.e3
   s/1.e6

.. ipython:: python
   :suppress:

   pd.reset_option('^display\.')