(self, t, force) 4469 "indexing.html#returning-a-view-versus-a-copy" 4470 ) 4471 4472 if value == "raise": -> 4473 raise SettingWithCopyError(t) 4474 if value == "warn": 4475 warnings.warn(t, SettingWithCopyWarning
5)) In [37]: arr[arr < .9] = 0 In [38]: sp_arr = csr_matrix(arr) In [39]: sp_arr Out[39]: <1000x5 sparse matrix of type '<class 'numpy.float64'>' with 517 stored elements in Compressed Sparse Row format> In [40]: sdf = pd.DataFrame.sparse.from_sp...
例如,对象数据类型序列最有用的方法之一是value_counts,它计算每个唯一值的所有出现次数: >>> director.value_counts()Steven Spielberg 26Woody Allen 22Martin Scorsese 20Clint Eastwood 20..Fatih Akin 1Analeine Cal y Mayor 1Andrew Douglas 1Scott Speer 1Name: director_name, Length: 2397, dtype: int64...
# Getting Value with boolean arraydf1.loc[:,df1.loc['b']>0] 以上的语句表达的含义为: 找到这样的Col的所有值, 这些col在 "b" index(row) 上的值应该大于0. 这个.loc索引语句是根据行值选择列. 如果单独执行b语句. 可以看出它返回的是对应各Col的 Boolean Series. df1.loc['b']>0 AFalseBTrue...
->5633new_index, indexer = ax.reindex(5634labels, level=level, limit=limit, tolerance=tolerance, method=method5635)5637axis = self._get_axis_number(a)5638obj = obj._reindex_with_indexers(5639{axis: [new_index, indexer]},5640fill_value=fill_value,5641copy=copy,5642allow_dups=False,5643)...
(f, axis="columns") File ~/work/pandas/pandas/pandas/core/frame.py:10374, in DataFrame.apply(self, func, axis, raw, result_type, args, by_row, engine, engine_kwargs, **kwargs) 10360 from pandas.core.apply import frame_apply 10362 op = frame_apply( 10363 self, 10364 func=func, ...
A value is trying to be set on a copy of a slice from a DataFrame. Try using .loc[row_indexer,col_indexer] = value instead 同时有网址传送: Indexing and selecting datapandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy 不建议使用链式索引传递 ...
pivot(index, columns, values) 根据此DataFrame的3列生成“pivot”表。 pivot_table(data[, values, index, columns, …]) 创建电子表格样式的透视表作为DataFrame架。 crosstab(index, columns[, values, rownames, …]) 计算两个(或更多)因素的简单交叉列表。 cut(x, bins[, right, labels, retbins, …...
value_counts(dropna=False) # 查看 DataFrame 对象中每一列的唯一值和计数 df.apply(pd.Series.value_counts) df.duplicated() # 重复行 df.drop_duplicates() # 删除重复行 # set_option、reset_option、describe_option 设置显示要求 pd.get_option() # 设置行列最大显示数量,None 为不限制 pd.options....
1. SettingWithCopyWarning: 当然这不是个异常,而是一个警告,这个警告相信大多数人都遇到过,尤其是初学pandas的时候。这个警告具体内容如下: SettingWithCopyWarning: Avalueistrying to besetona copy of a slicefroma DataFrame. Tryusing.loc[row_indexer,col_indexer] =valueinstead ...