df.iloc[row_index, column_index] # 通过标签或位置选择数据 df.ix[row_index, column_name] # 选择指定的列 df.filter(items=['column_name1', 'column_name2']) # 选择列名匹配正则表达式的列 df.filter(regex='regex') # 随机选择 n 行数据 df.sample(n=5)数据...
apply()将一个函数作用于DataFrame中的每个行或者列 df = df2.filter(regex='[^a-z]', axis=1).apply(lambda x: x*2) Applymap() 将函数做用于DataFrame中的所有元素(elements) 例如,在所有元素前面加个字符A def addA(x): return "A" + str(x) df.applymap(addA) 4.3 独热编码与随机抽样 ...
df[columnname]:标示一个Series df[[columnname]]:标示一个DataFrame DataFrame可以用join函数进行拼接,而Series则不行 六。df拼接:join df.join(other, on=None, how='left', lsuffix='', rsuffix='', sort=False) 将df 和other按列合并, on:None代表是按照索引index进行匹配合并 columnsname:按照列进行...
filter(regex = 'e$') # 保留列标签是以e结尾的所有列 filter参数解析:items:精确匹配,保留标签/索引为列表中所列的值的行或者列,items的值为列表,默认为None。like:模糊匹配,保留了标签/索引含有所列字符串内字符的行或者列,like的值为str,默认为None。regex:正则匹配,默认为None。axis:确定要进行筛选的是...
As theregexis defined, we have to use the following piece of code for filtering DataFrame rows: dataframe.column_name.str.match(regex) Note To work with pandas, we need to importpandaspackage first, below is the syntax: import pandas as pd ...
filter(regex='\d').head() Out[10]: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 # filter()函数,传递列表到参数items,选取多列 In[11]: movie.filter(items=['actor_1_name', 'asdf']).head() Out[11]: 2. 对列名进行排序 代码语言:javascript 代码运行次数:0 运行 AI代码解释 # 读取...
DataFrame.filter([items, like, regex, axis])过滤特定的子数据框 DataFrame.first(offset)Convenience method for subsetting initial periods of time series data based on a date offset. DataFrame.head([n])返回前n行 DataFrame.idxmax([axis, skipna])Return index of first occurrence of maximum over re...
replace(to_replace=None, value=None, inplace=False, limit=None, regex=False, method='pad') 参数解释: to_replace:被替换的值 value:替换后的值 inplace:是否要改变原数据,False是不改变,True是改变,默认是False limit:控制填充次数 regex:是否使用正则,False是不使用,True是使用,默认是False method:填充...
Regex filtering on String Column Filters Editing Cells Data Reshaping Dataframe Functions Drop Filtered Rows Sorting If the symbol you're loading from ArcticDB contains more than 1,000,000 rows then you will also lose the following: Column Filtering using dropdowns of unique values (you'll have...
By using pandas DataFrame.astype() and pandas.to_numeric() methods you can convert a column from string/int type to float. In this article, I will explain