20,30],'C':['pandasdataframe.com','modify','columns']})# 定义一个函数,如果数值大于10,加10defadd_ten(x):returnx+10ifx>10elsex# 对'A'和'B'列应用条件函数df[['A','B']]=df[['A','B']].applymap(add_ten)print(df)
df.info() # 查看索引、数据类型和内存信息 df.columns() # 查看字段()名称 df.describe() # 查看汇总统计 s.value_counts() # 统计某个值出现次数 df.apply(pd.Series.value_counts) # 查看DataFrame对象中每列的唯值和计数 df.isnull().any() # 查看是否有缺失值 df[df[column_name].duplicated()...
axis='columns',level=-1)self=data.xs('self',axis='columns',level=-1)returnpd.DataFrame(np.where(self!=other,attr,''),index=data.index,columns=data.columns)comparison.style.apply(highlight_diff,axis=None)
方便后面的groupby.rename(columns={"level_1":"mate_type"})# 这一步也可以不做，不做的话后面就...
6 rows x 16 columns] Another aggregation example is to compute the number of unique values of each group. This is similar to thevalue_countsfunction, except that it only counts unique values. In [77]: ll = [['foo', 1], ['foo', 2], ['foo', 2], ['bar', 1], ['bar', 1]...
一、前言二、本文概要三、pandas merge by 修罗闪空3.1 merge函数用途3.2 merge函数的具体参数3.3 merge函数的应用四、pandas apply by pluto、乔瞧4.1 pandas apply by pluto4.2 pandas apply by 乔瞧pandas pivot_table by 石墨锡 一、前言 本文来自四位读者的合作,这四位读者是之前推文14个pandas神操作,手把手...
df.index|columns = df.index|columns.map(Function) #对索引值使用函数进行转换 二、离散数据分组 1、普通分组:cut cats = pd.cut(x, bins, right=True, labels=None, retbins=False, precision=3, include_lowest=False) Return indices of half-open bins to which each value of `x` belongs. x:必...
读数据用read_csv，这是最常用的函数。比如从本地文件读取学生信息表，直接写pd.read_csv(’students.csv’)就行，自动识别分隔符和表头。如果文件没有列名，可以加个header=None参数，再手动指定列名。有时候数据量太大，想先看看前几行，head()就派上用场，默认显示前五行，想看更多可以传参数比如head(10)。
The Python function should take a pandas Series as an input and return a pandas Series of the same length, and you should specify these in the Python type hints. Spark runs a pandas UDF by splitting columns into batches, calling the function for each batch as a subset of the data, then...
# 自定义一个求SAT数学成绩的加权平均值的函数 In[76]:defweighted_math_average(df):weighted_math=df['UGDS']*df['SATMTMID']returnint(weighted_math.sum()/df['UGDS'].sum())# 按州分组,并调用apply方法,传入自定义函数 In[77]:college2.groupby('STABBR').apply(weighted_math_average).head(...