Reduction in the dimensions of the returned objectFor getting a scalar valueScalar(标量)是只有大小,没有方向的量,所以可以用实数表示的一个量。 标量可以是负数,例如温度低于冰点。 与之相对,Vector(向量,又称矢量)既有大小,又有方向。 For getting fast access to a sc
d={'a':0.,'b':1.,'c':2.}pd.Series(d)a0.0b1.0c2.0dtype:float64pd.Series(d,index=['b','c','d','a'])b1.0c2.0dNaNa0.0dtype:float64NaN(notanumber)是pandas中使用的标准缺失数据标记。3.从scalarvalue标量值如果数据是一个标量值,必须提供一个索引。该值将被重复以匹配索引的长度。pd...
In [29]:df.loc['20130102',['A','B']]Out[29]:A 1.212112B -0.173215Name: 2013-01-02 00:00:00, dtype: float64 For getting a scalar value In [30]:df.loc[dates[0],'A']Out[30]:0.46911229990718628 For getting fast access to a scalar (equiv to the prior method) In [31]:df.at...
方法get_level_values()将返回特定级别上每个位置的标签向量: 代码语言:javascript 代码运行次数:0 运行 复制 In [23]: index.get_level_values(0) Out[23]: Index(['bar', 'bar', 'baz', 'baz', 'foo', 'foo', 'qux', 'qux'], dtype='object', name='first') In [24]: index.get_level_...
For getting a scalar value In [30]: df.loc[dates[0],'A'] Out[30]: 0.46911229990718628 1. 2. For getting fast access to a scalar (equiv to the prior method) In [31]: df.at[dates[0],'A'] Out[31]: 0.46911229990718628 1. 2. Selection by Position See more in Selection by Positi...
(start, end, step=step) 6664 # return a slice 6665 if not is_scalar(start_slice): File ~/work/pandas/pandas/pandas/core/indexes/base.py:6879, in Index.slice_locs(self, start, end, step) 6877 start_slice = None 6878 if start is not None: -> 6879 start_slice = self.get_slice_...
pd.DataFrame.fillna(value='None', method='None', axis='None'):用某种方法(‘backfill’, ‘bfill’ // ‘pad’, ‘ffill’)填补缺失值;value要是scalar、dict、Series、DataFame,不能是list 按条件清洗 pd.DataFrame.replace(to_replace='None',value='None'):用value的值去取代to_replace的值;to_re...
na_valuesscalar、str、类似列表或字典,默认为None 附加字符串识别为 NA/NaN。如果传递字典,则为每列指定特定的 NA 值。有关默认解释为 NaN 的值列表,请参见 na values const。 keep_default_naboolean,默认为True 是否在解析数据时包括默认的 NaN 值。根据是否传入na_values,行为如下: ...
pd.DataFrame.fillna(value='None', method='None', axis='None'):用某种方法(‘backfill’, ‘bfill’ // ‘pad’, ‘ffill’)填补缺失值;value要是scalar、dict、Series、DataFame,不能是list 按条件清洗 pd.DataFrame.replace(to_replace='None',value='None'):用value的值去取代to_replace的值;to_re...
_scalar: -> 1121 return self._get_value(key) 1123 # Convert generator to list before going through hashable part 1124 # (We will iterate through the generator there to check for slices) 1125 if is_iterator(key): File ~/work/pandas/pandas/pandas/core/series.py:1237, in Series._get_...