SELECT*,CASEWHENchinese_score>=90AND math_score>=90THEN'A'WHENchinese_score>=80AND math_score>=80THEN'B'ELSE'C'ENDASscore_typeFROMscores 如果用pandas apply方法来实现的话,需要自定义一个判断函数,用来对成绩进行分类。 然后用apply方法应用到dataframe上,以下是完整代码,可以放到本地电脑跑。 代码语言...
A pandasDataFrameis a two (or more) dimensional data structure – basically a table with rows and columns. The columns have names and the rows have indexes. Compared to a pandas Series (which was one labeled column only), a DataFrame is practically the whole data table. You can think of ...
数据管理 演示数据集 # Create a dataframe import pandas as pd import numpy as np raw_data = {'first_name': ['Jason', 'Molly', np.nan, np
ser) print("DataFrame df13:", pd.DataFrame(ser)) # Series 里面定义的name,就是DataFrame里面的列 名称 print("DataFrame df14:", pd.DataFrame(ser, columns=["ser"])) print("DataFrame df15:", pd.DataFrame(ser, columns=["ser", "name2"])) ...
DataFrame([[30, 21],[40, 22]], columns=['Apples', 'Bananas']) 字典内的value也可以是:字符串 代码语言:javascript 代码运行次数:0 运行 AI代码解释 pd.DataFrame({"Michael":['handsome','good'],"Ming":['love basketball','coding']}) 给数据加索引index,index=['index1','index2',...] ...
更简单的方式就是重写DataFrame的columns属性：In [15]: df.columns = ['col_one', 'col_two']...
我有一个带有以下示例列的数据框架。 我在日期栏中有一个每日数据。我想添加一列,该列具有基于日期的特定值。 如果日期在29之前,则应在新的日期范围列中包含12/29之前的值,30之后表示应包含12/30之后的值,与其他值相同。 Date product result 12/27/2021 tv 6 ...
{SQL Server};SERVER='+server+';DATABASE='+database+';UID='+username+';PWD='+ password) cursor = cnxn.cursor()# select 26 rows from SQL table to insert in dataframe.query ="SELECT [CountryRegionCode], [Name] FROM Person.CountryRegion;"df = pd.read_sql(query, cnxn) print(df.head...
Example 1: Insert New Column in the Middle of pandas DataFrameThe Python code below illustrates how to insert a list as a new variable in between a pandas DataFrame.For this task, we can apply the insert function as shown below. Within the insert function, we have to specify the index ...
A step-by-step Python code example that shows how to select rows from a Pandas DataFrame based on a column's values. Provided by Data Interview Questions, a mailing list for coding and data interview problems.