. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 25 API Reference 437 25.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mac all stable All platforms pip install pandas Linux Debian stable official Debian repository sudo apt-get install python-pandas Linux Debian & Ubuntu unstable (latest packages) NeuroDebian sudo apt-get of BeautifulSoup4: * Versions 4.2.1, 4.1.3 and 4.0.2 have been confirmed for 64 and 32-bit Ubuntu/Debian – Additionally, if you’re using Anaconda you should definitely read the gotchas about HTML parsing

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583 28 API Reference 585 28.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2013-01-09 -0.933857 -0.030896 2013-01-10 -0.012390 0.253387 [6 rows x 2 columns] Use an inline column reference In [43]: read_hdf(path,’dfq’, ....: where="A>0 or C>0") ....: Out[43]: A B C D 2013-01-01 ’piecewise_polynomial’, ’pchip’, ‘polynomial‘, ’spline’ The new methods re- quire scipy. Consult the Scipy reference guide and documentation for more information about when the various methods are appropriate. See

Distribution Status Download / Reposi- tory Link Install method Debian stable official Debian reposi- tory sudo apt-get install python3-pandas Debian & Ubuntu unstable (latest pack- ages) NeuroDebian sudo 44982 0.930166 1.063425 c 2.45953 0.848864 -0.169812 d NaN 1.438805 0.683321 Here is a quick reference summary table of common functions. Each also takes an optional level parameter which applies only Passing a callable, as opposed to an actual value to be inserted, is useful when you dont have a reference to the DataFrame at hand. This is common when using assign in a chain of operations. For example

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 645 28 API Reference 647 28.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2013-01-09 1.529401 0.205455 2013-01-10 0.299071 1.076541 [6 rows x 2 columns] Use an inline column reference In [43]: read_hdf(path,’dfq’, ....: where="A>0 or C>0") ....: Out[43]: A B C D 44 Chapter ’piecewise_polynomial’, ’pchip’, ‘polynomial‘, ’spline’ The new methods re- quire scipy. Consult the Scipy reference guide and documentation for more information about when the various methods are appropriate. See

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 797 32 API Reference 799 32.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DataFrame.stack(..., dropna=False) when the DataFrame’s columns is a MultiIndex whose labels do not reference all its levels. (GH8844) • Bug in that Option context applied on __enter__ (GH8514) • Bug in resample prior to v0.15.0 # the original object In [5]: s Out[5]: 0 2.5 1 3.5 2 4.5 dtype: float64 # a reference to the original object In [7]: s2 Out[7]: 0 1 1 2 2 3 dtype: int64 This is now the correct behavior

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783 32 API Reference 785 32.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . prior to v0.15.0 # the original object In [5]: s Out[5]: 0 2.5 1 3.5 2 4.5 dtype: float64 # a reference to the original object In [7]: s2 Out[7]: 0 1 1 2 2 3 dtype: int64 This is now the correct behavior behavior # the original object In [101]: s Out[101]: 0 2.5 1 3.5 2 4.5 dtype: float64 # a reference to the original object 24 Chapter 1. What’s New pandas: powerful Python data analysis toolkit

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 934 34 API Reference 935 34.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DataFrame.stack(..., dropna=False) when the DataFrame’s columns is a MultiIndex whose labels do not reference all its levels. (GH8844) • Bug in that Option context applied on __enter__ (GH8514) • Bug in resample prior to v0.15.0 # the original object In [5]: s Out[5]: 0 2.5 1 3.5 2 4.5 dtype: float64 # a reference to the original object In [7]: s2 Out[7]: 0 1 1 2 2 3 dtype: int64 This is now the correct behavior

. . . . . . . . . . . . . . . . . . 1052 32 Comparison with R / R libraries 1053 32.1 Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1053 32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1090 xxi 35 API Reference 1091 35.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DataFrame.stack(...,dropna=False) when the DataFrame’s columns is a MultiIndex whose labels do not reference all its levels. (GH8844) • Bug in that Option context applied on __enter__ (GH8514) • Bug in resample

. . . . . . . . . . . . . . . . . . 1144 31 Comparison with R / R libraries 1145 31.1 Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1145 31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1182 34 API Reference 1185 34.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to_datetime() has gained an origin parameter to_datetime() has gained a new parameter, origin, to define a reference date from where to compute the resulting timestamps when parsing numerical values with a specific

. . . . . . . . . . . . . . . . . . 1050 32 Comparison with R / R libraries 1051 32.1 Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1051 32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1088 35 API Reference 1089 xxi 35.1 Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DataFrame.stack(...,dropna=False) when the DataFrame’s columns is a MultiIndex whose labels do not reference all its levels. (GH8844) • Bug in that Option context applied on __enter__ (GH8514) • Bug in resample