50000, 60000, 70000] }) # 选择单独的一列,返回一个 Series 对象 age_column = df['Age'] print(age_column) # 选择多个列,返回一个新的 DataFrame 对象 subset_df = df[['Name', 'Sex', 'Income']] print(subset_df) 通过标签选择(loc) 通过标签选择的语法格
data['new_column'] = data['string_column'].str.contains('substring') 其中,'new_column'是新列的名称,'string_column'是包含字符串的列的名称,'substring'是要检查的子字符串。 查看结果:可以使用head()函数查看新列的前几行,以确保新列已成功创建。
'State':['NY','TX','FL','AL','AK','TX','TX']},index=['Jane','Pane','Aaron','Penelope','Frane','Christina','Cornelia'])print(df)print("\n--- Filter Index contains ane ---\n")df.index=df.index.
对分组后结果过滤,保留满足条件的分组:filter() #想要找到哪个月只有一个人过生日 df.groupby(df["生日"].apply(lambda x:x.month),as_index=False) # 按月分组,保持原来的数据索引结果不变 df.groupby(df["生日"].apply(lambda x:x.month),as_index=False).filter(lambda x: len(x)==1) #对分组进...
.filter(pl.col("Category").is_in(["A","B"])) ) 如果表达式是 Eager 执行,则会多余地对整个 DataFrame 执行 groupby 运算,然后按 Category 筛选。 通过惰性执行,DataFrame 会先经过筛选,并仅对所需数据执行 groupby。 4)表达性 API 最后,Polars 拥有一个极具表达性的 API,基本上你想执行的任何运算都...
Python program to determine whether a Pandas Column contains a particular value # Import pandas Packageimportpandasaspd# Creating dictionaryd={'Name':['Ankit','Tushar','Saloni','Jyoti','Anuj','Rajat'],'Age':[23,21,22,21,24,25],'University':['BHU','JNU','DU','BHU','Geu','Geu']...
For this purpose, we will first check if a column contains a NaN value or not by using theisna()method and then we will collect all the names of the column containingNaNvalues into a list by using thetolist()method. Note To work with pandas, we need to importpandaspackage first,...
To filter the dataframe where a column value isNULL, use.isnull() importpandasaspdimportnumpyasnp df = pd.DataFrame({'name':['john','david','anna'],'country':['USA','UK',np.nan] }) df.query('country.isnull()') Original Dataframe ...
{column -> value}] - 'index' : dict like {index -> {column -> value}} - 'columns' : dict like {column -> {index -> value}} - 'values' : just the values array - 'table' : dict like {'schema': {schema}, 'data': {data}} Describing the data, where data component is ...
str.contains("Python")# 提取列名df.columns# 查看某列唯一值(种类)df['education'].nunique()# 删除重复数据df.drop_duplicates(inplace=True)# 某列等于某值df[df.col_name==0.587221]# df.col_name==0.587221 各行判断结果返回值(True/False)# 查看某列唯一值及计数df_jj2["变压器编号"].value_...