U
    b/                     @  s   d Z ddlmZ ddlmZ ddlZddlmZ ddl	m
Z
 ddlmZ ddlmZ d	ZG d
d dZG dd deZG dd deZG dd deZG dd deZG dd deZG dd deZG dd deZdS )zLIndexer objects for computing start/end window bounds for rolling operations    )annotations)	timedeltaN) calculate_variable_window_bounds)Appender)ensure_platform_int)Nanoa\  
Computes the bounds of a window.

Parameters
----------
num_values : int, default 0
    number of values that will be aggregated over
window_size : int, default 0
    the number of rows in a window
min_periods : int, default None
    min_periods passed from the top level rolling API
center : bool, default None
    center passed from the top level rolling API
closed : str, default None
    closed passed from the top level rolling API
win_type : str, default None
    win_type passed from the top level rolling API

Returns
-------
A tuple of ndarray[int64]s, indicating the boundaries of each
window
c                   @  sB   e Zd ZdZddddddZeeddd	d
dddddZdS )BaseIndexerz*Base class for window bounds calculations.Nr   np.ndarray | Noneintindex_arraywindow_sizec                 K  s.   || _ || _| D ]\}}t| || qdS )z
        Parameters
        ----------
        **kwargs :
            keyword arguments that will be available when get_window_bounds is called
        N)r   r   itemssetattr)selfr   r   kwargskeyvalue r   @/tmp/pip-unpacked-wheel-xg7vt6ln/pandas/core/indexers/objects.py__init__+   s    	zBaseIndexer.__init__
int | Nonebool | None
str | Nonetuple[np.ndarray, np.ndarray]
num_valuesmin_periodscenterclosedreturnc                 C  s   t d S N)NotImplementedErrorr   r   r   r   r   r   r   r   get_window_bounds:   s    	zBaseIndexer.get_window_bounds)Nr   )r   NNN)__name__
__module____qualname____doc__r   r   get_window_bounds_docr$   r   r   r   r   r   (   s          r   c                   @  s0   e Zd ZdZeeddddddd	d
dZdS )FixedWindowIndexerz3Creates window boundaries that are of fixed length.r   Nr
   r   r   r   r   r   c                 C  s   |r| j d d }nd}tjd| |d | dd}|| j  }|dkrN|d8 }|dkr^|d8 }t|d|}t|d|}||fS )N      r   int64Zdtypeleftboth)r0   Zneither)r   nparangeZclip)r   r   r   r   r   offsetendstartr   r   r   r$   I   s    	
z$FixedWindowIndexer.get_window_bounds)r   NNNr%   r&   r'   r(   r   r)   r$   r   r   r   r   r*   F   s       r*   c                   @  s0   e Zd ZdZeeddddddd	d
dZdS )VariableWindowIndexerzNCreates window boundaries that are of variable length, namely for time series.r   Nr
   r   r   r   r   r   c                 C  s   t || j|||| jS r!   )r   r   r   r#   r   r   r   r$   g   s    z'VariableWindowIndexer.get_window_bounds)r   NNNr7   r   r   r   r   r8   d   s       r8   c                      sJ   e Zd ZdZdddd fddZeeddd	d
dddddZ  ZS )VariableOffsetWindowIndexerzNCalculate window boundaries based on a non-fixed offset such as a BusinessDay.Nr   r	   r
   r   c                   s"   t  j||f| || _|| _d S r!   )superr   indexr4   )r   r   r   r;   r4   r   	__class__r   r   r      s    z$VariableOffsetWindowIndexer.__init__r   r   r   r   r   c                 C  s~  |d kr| j d k	rdnd}|dk}|dk}| j |d  | j d k rHd}nd}tj|dd	}|d tj|dd	}	|	d d|d< |rd|	d< nd|	d< td|D ]}
| j |
 }| j |
 || j  }|r|td8 }|
||
< t||
d  |
D ],}| j | | | tdkr|||
<  qq| j |	|
d   | | tdkrP|
d |	|
< n|	|
d  |	|
< |s|	|
  d8  < q||	fS )
Nrightr1   )r>   r1   r/   r+   r   r-   r.   )r;   r2   emptyfillranger4   r   r   )r   r   r   r   r   Zright_closedZleft_closedZindex_growth_signr6   r5   iZ	end_boundZstart_boundjr   r   r   r$      s>    




$z-VariableOffsetWindowIndexer.get_window_bounds)Nr   NN)r   NNN)	r%   r&   r'   r(   r   r   r)   r$   __classcell__r   r   r<   r   r9   ~   s           r9   c                   @  s0   e Zd ZdZeeddddddd	d
dZdS )ExpandingIndexerz;Calculate expanding window bounds, mimicking df.expanding()r   Nr
   r   r   r   r   r   c                 C  s&   t j|t jdt jd|d t jdfS )Nr.   r+   )r2   zerosr-   r3   r#   r   r   r   r$      s    
z"ExpandingIndexer.get_window_bounds)r   NNNr7   r   r   r   r   rF      s       rF   c                   @  s0   e Zd ZdZeeddddddd	d
dZdS )FixedForwardWindowIndexera  
    Creates window boundaries for fixed-length windows that include the
    current row.

    Examples
    --------
    >>> df = pd.DataFrame({'B': [0, 1, 2, np.nan, 4]})
    >>> df
         B
    0  0.0
    1  1.0
    2  2.0
    3  NaN
    4  4.0

    >>> indexer = pd.api.indexers.FixedForwardWindowIndexer(window_size=2)
    >>> df.rolling(window=indexer, min_periods=1).sum()
         B
    0  1.0
    1  3.0
    2  2.0
    3  4.0
    4  4.0
    r   Nr
   r   r   r   r   r   c                 C  sR   |rt d|d k	rt dtj|dd}|| j }| jrJ||| j d < ||fS )Nz.Forward-looking windows can't have center=TruezAForward-looking windows don't support setting the closed argumentr-   r.   )
ValueErrorr2   r3   r   )r   r   r   r   r   r6   r5   r   r   r   r$      s    	
z+FixedForwardWindowIndexer.get_window_bounds)r   NNNr7   r   r   r   r   rH      s       rH   c                      sZ   e Zd ZdZdddedfdddddd fd	d
ZeedddddddddZ  Z	S )GroupbyIndexerzMCalculate bounds to compute groupby rolling, mimicking df.groupby().rolling()Nr   r	   zint | BaseIndexerzdict | Noneztype[BaseIndexer])r   r   groupby_indiceswindow_indexerindexer_kwargsc                   sH   |pi | _ || _|r| ni | _t jf || jd|d| dS )a4  
        Parameters
        ----------
        index_array : np.ndarray or None
            np.ndarray of the index of the original object that we are performing
            a chained groupby operation over. This index has been pre-sorted relative to
            the groups
        window_size : int or BaseIndexer
            window size during the windowing operation
        groupby_indices : dict or None
            dict of {group label: [positional index of rows belonging to the group]}
        window_indexer : BaseIndexer
            BaseIndexer class determining the start and end bounds of each group
        indexer_kwargs : dict or None
            Custom kwargs to be passed to window_indexer
        **kwargs :
            keyword arguments that will be available when get_window_bounds is called
        r   r   N)rK   rL   copyrM   r:   r   pop)r   r   r   rK   rL   rM   r   r<   r   r   r     s    
zGroupbyIndexer.__init__r
   r   r   r   r   r   c                 C  s*  g }g }d}| j  D ]\}}	| jd k	r:| jt|	}
n| j}
| jf |
| jd| j}|t	|	|||\}}|
tj}|
tj}t	|t	|kstdt||t	|	 }|t	|	7 }t||d d gj
tjdd}||t| ||t| qt|}t|}||fS )Nr   r   z6these should be equal in length from get_window_boundsr?   r+   F)rN   )rK   r   r   Ztaker   rL   r   rM   r$   lenZastyper2   r-   AssertionErrorr3   appendZconcatenate)r   r   r   r   r   Zstart_arraysZ
end_arraysZwindow_indices_startr   indicesr   Zindexerr6   r5   Zwindow_indicesr   r   r   r$   ;  sP    
    
 

z GroupbyIndexer.get_window_bounds)r   NNN)
r%   r&   r'   r(   r   r   r   r)   r$   rE   r   r   r<   r   rJ     s   $    rJ   c                   @  s0   e Zd ZdZeeddddddd	d
dZdS )ExponentialMovingWindowIndexerz/Calculate ewm window bounds (the entire window)r   Nr
   r   r   r   r   r   c                 C  s$   t jdgt jdt j|gt jdfS )Nr   r.   )r2   arrayr-   r#   r   r   r   r$   q  s    	z0ExponentialMovingWindowIndexer.get_window_bounds)r   NNNr7   r   r   r   r   rT   n  s       rT   )r(   
__future__r   datetimer   Znumpyr2   Zpandas._libs.window.indexersr   Zpandas.util._decoratorsr   Zpandas.core.dtypes.commonr   Zpandas.tseries.offsetsr   r)   r   r*   r8   r9   rF   rH   rJ   rT   r   r   r   r   <module>   s    R2Z