def hist_series(self, by=None, ax=None, grid=True, xlabelsize=None,<EOL>xrot=None, ylabelsize=None, yrot=None, figsize=None,<EOL>bins=<NUM_LIT:10>, **kwds):
import matplotlib.pyplot as plt<EOL>if by is None:<EOL><INDENT>if kwds.get('<STR_LIT>', None) is not None:<EOL><INDENT>raise ValueError("<STR_LIT>"<EOL>"<STR_LIT>")<EOL><DEDENT>fig = kwds.pop('<STR_LIT>', plt.gcf() if plt.get_fignums() else<EOL>plt.figure(figsize=figsize))<EOL>if (figsize is not None and tuple(figsize) !=<EOL>tuple(fig.get_size_inches())):<EOL><INDENT>fig.set_size_inches(*figsize, forward=True)<EOL><DEDENT>if ax is None:<EOL><INDENT>ax = fig.gca()<EOL><DEDENT>elif ax.get_figure() != fig:<EOL><INDENT>raise AssertionError('<STR_LIT>')<EOL><DEDENT>values = self.dropna().values<EOL>ax.hist(values, bins=bins, **kwds)<EOL>ax.grid(grid)<EOL>axes = np.array([ax])<EOL>_set_ticks_props(axes, xlabelsize=xlabelsize, xrot=xrot,<EOL>ylabelsize=ylabelsize, yrot=yrot)<EOL><DEDENT>else:<EOL><INDENT>if '<STR_LIT>' in kwds:<EOL><INDENT>raise ValueError("<STR_LIT>"<EOL>"<STR_LIT>"<EOL>"<STR_LIT>")<EOL><DEDENT>axes = grouped_hist(self, by=by, ax=ax, grid=grid, figsize=figsize,<EOL>bins=bins, xlabelsize=xlabelsize, xrot=xrot,<EOL>ylabelsize=ylabelsize, yrot=yrot, **kwds)<EOL><DEDENT>if hasattr(axes, '<STR_LIT>'):<EOL><INDENT>if axes.ndim == <NUM_LIT:1> and len(axes) == <NUM_LIT:1>:<EOL><INDENT>return axes[<NUM_LIT:0>]<EOL><DEDENT><DEDENT>return axes<EOL>
Draw histogram of the input series using matplotlib.

Parameters
----------
by : object, optional
    If passed, then used to form histograms for separate groups
ax : matplotlib axis object
    If not passed, uses gca()
grid : bool, default True
    Whether to show axis grid lines
xlabelsize : int, default None
    If specified changes the x-axis label size
xrot : float, default None
    rotation of x axis labels
ylabelsize : int, default None
    If specified changes the y-axis label size
yrot : float, default None
    rotation of y axis labels
figsize : tuple, default None
    figure size in inches by default
bins : integer or sequence, default 10
    Number of histogram bins to be used. If an integer is given, bins + 1
    bin edges are calculated and returned. If bins is a sequence, gives
    bin edges, including left edge of first bin and right edge of last
    bin. In this case, bins is returned unmodified.
bins : integer, default 10
    Number of histogram bins to be used
`**kwds` : keywords
    To be passed to the actual plotting function

See Also
--------
matplotlib.axes.Axes.hist : Plot a histogram using matplotlib.