The pivot function is purely restructuring of the data, pivot_table supports aggregations • The reverse of pivot (long to wide format) is melt (wide to long format) A full overview is available in the 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [44]: s2.str.rsplit("_" 2.9. Working with text data 583 pandas: powerful Python data analysis toolkit, Release 1.4.2 # Reverse every lowercase alphabetic word In [51]: pat = r"[a-z]+" In [52]: def repl(m): ....: return m.group(0)[::-1]

The pivot function is purely restructuring of the data, pivot_table supports aggregations • The reverse of pivot (long to wide format) is melt (wide to long format) A full overview is available in the 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [44]: s2.str.rsplit("_" 2.9. Working with text data 583 pandas: powerful Python data analysis toolkit, Release 1.4.4 # Reverse every lowercase alphabetic word In [51]: pat = r"[a-z]+" In [52]: def repl(m): ....: return m.group(0)[::-1]

indexing with a non lex-sorted MultiIndex (GH13797) • Bug in .loc when indexing with date strings in a reverse sorted DatetimeIndex (GH14316) • Bug in Series comparison operators when dealing with zero dim NumPy (GH6531): – df.iloc[:-len(df)] is now empty – df.iloc[len(df)::-1] now enumerates all elements in reverse • The DataFrame.interpolate() keyword downcast default has been changed from infer to None. This create a table from DataFrame and Series, and add it to an matplotlib.Axes. • plot(legend='reverse') will now reverse the order of legend labels for most plot kinds. (GH6014) • Line plot and area plot can

The pivot function is purely restructuring of the data, pivot_table supports aggregations. • The reverse of pivot (long to wide format) is melt (wide to long format). A full overview is available in the 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [44]: s2.str.rsplit("_" sub(). The callable should expect one positional argument (a regex object) and return a string. # Reverse every lowercase alphabetic word In [51]: pat = r"[a-z]+" In [52]: def repl(m): ....: return m.group(0)[::-1]

The pivot function is purely restructuring of the data, pivot_table supports aggregations • The reverse of pivot (long to wide format) is melt (wide to long format) A full overview is available in the 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [44]: s2.str.rsplit('_' sub(). The callable should expect one positional argument (a regex object) and return a string. # Reverse every lowercase alphabetic word In [54]: pat = r'[a-z]+' In [55]: def repl(m): ....: return m.group(0)[::-1]

The pivot function is purely restructuring of the data, pivot_table supports aggregations • The reverse of pivot (long to wide format) is melt (wide to long format) A full overview is available in the 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [44]: s2.str.rsplit('_' sub(). The callable should expect one positional argument (a regex object) and return a string. # Reverse every lowercase alphabetic word In [54]: pat = r'[a-z]+' In [55]: def repl(m): ....: return m.group(0)[::-1]

indexing with a non lex-sorted MultiIndex (GH13797) • Bug in .loc when indexing with date strings in a reverse sorted DatetimeIndex (GH14316) • Bug in Series comparison operators when dealing with zero dim NumPy (GH6531): – df.iloc[:-len(df)] is now empty – df.iloc[len(df)::-1] now enumerates all elements in reverse • The DataFrame.interpolate() keyword downcast default has been changed from infer to None. This create a table from DataFrame and Series, and add it to an matplotlib.Axes. • plot(legend='reverse') will now reverse the order of legend labels for most plot kinds. (GH6014) • Line plot and area plot can

where equality comparisons were incorrect (GH24112) 1.9.9 Indexing • Bug in assignment using a reverse slicer (GH26939) • Bug in DataFrame.explode() would duplicate frame in the presence of duplicates 0 1 0 a b_c 1 c d_e 2 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [36]: s2.str.rsplit('_' sub(). The callable should expect one positional argument (a regex object) and return a string. # Reverse every lowercase alphabetic word In [46]: pat = r'[a-z]+' In [47]: def repl(m): ....: return m.group(0)[::-1]

Out[20]: 0 1 0 a b_c 1 c d_e 2 NaN NaN 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [21]: s2.str.rsplit('_' 6. Working with text data 491 pandas: powerful Python data analysis toolkit, Release 0.25.0 # Reverse every lowercase alphabetic word In [31]: pat = r'[a-z]+' In [32]: def repl(m): ....: return m.group(0)[::-1] NaN 1.0 rank optionally takes a parameter ascending which by default is true; when false, data is reverse-ranked, with larger values assigned a smaller rank. rank supports different tie-breaking methods

Out[20]: 0 1 0 a b_c 1 c d_e 2 NaN NaN 3 f g_h rsplit is similar to split except it works in the reverse direction, i.e., from the end of the string to the beginning of the string: In [21]: s2.str.rsplit('_' 6. Working with text data 491 pandas: powerful Python data analysis toolkit, Release 0.25.1 # Reverse every lowercase alphabetic word In [31]: pat = r'[a-z]+' In [32]: def repl(m): ....: return m.group(0)[::-1] NaN 3.0 rank optionally takes a parameter ascending which by default is true; when false, data is reverse-ranked, with larger values assigned a smaller rank. rank supports different tie-breaking methods