python df中删除is_new列的值是N的行

可以使用 Pandas 的 drop 方法来删除符合特定条件的行。假设你的 DataFrame 名称为 df，可以使用以下代码删除 is_new 列的值为 N 的行：

df = df.drop(df[df['is_new'] == 'N'].index)

这将返回一个新的 DataFrame，其中包含已删除指定行的所有其他行。如果你希望更新原始 DataFrame，则可以添加 inplace 参数：

df.drop(df[df['is_new'] == 'N'].index, inplace=True)

相关问题

转化为Python操作数据库的代码 new_b_df.withColumn("score", new_b_df['stars'] * 100 + new_b_df['review_count']) \ .where(new_b_df['is_open'] == 1) \ .select(col('name'), col('score')) \ .orderBy(col('score').desc()).show(1500, truncate=False)

以下是使用Python操作数据库的代码示例：

from pyspark.sql import SparkSession
from pyspark.sql.functions import col

# 创建SparkSession对象
spark = SparkSession.builder.appName('example').getOrCreate()

# 从数据库中读取数据
df = spark.read.format('jdbc').options(
    url='jdbc:mysql://localhost:3306/example',
    driver='com.mysql.jdbc.Driver',
    dbtable='business',
    user='root',
    password='123456'
).load()

# 对数据进行处理
new_b_df = df.withColumn("score", df['stars'] * 100 + df['review_count']) \
              .where(df['is_open'] == 1) \
              .select(col('name'), col('score')) \
              .orderBy(col('score').desc())

# 将结果保存到数据库中
new_b_df.write.format('jdbc').options(
    url='jdbc:mysql://localhost:3306/example',
    driver='com.mysql.jdbc.Driver',
    dbtable='result',
    user='root',
    password='123456'
).mode('overwrite').save()

需要注意的是，此示例代码仅供参考，具体实现方式可能因数据库类型、版本等因素而有所不同。

请帮我把这段python代码转为sql命令，df对应表格common_goods.fund_objectives_strategy_with_labels：# Assuming period_end_date data is in a pandas DataFrame called 'df' with a column called 'period_end_date' df['period_end_date'] = pd.to_datetime(df['period_end_date'], format='%Y%m%d') # Convert time column to datetime format df['year'] = df['period_end_date'].dt.year # Create a new column with the year df['last_entry'] = df.groupby('year')['period_end_date'].transform('max') == df['period_end_date'] # Create a new column indicating if the entry is the last for that year df['last_entry'] = df['last_entry'].astype(int) # Convert True/False to 1/0

UPDATE common_goods.fund_objectives_strategy_with_labels
SET period_end_date = STR_TO_DATE(period_end_date, '%Y%m%d');

UPDATE common_goods.fund_objectives_strategy_with_labels
SET year = YEAR(period_end_date);

UPDATE common_goods.fund_objectives_strategy_with_labels
SET last_entry = IF((SELECT MAX(period_end_date) FROM common_goods.fund_objectives_strategy_with_labels WHERE YEAR(period_end_date) = t.year) = t.period_end_date, 1, 0)
FROM common_goods.fund_objectives_strategy_with_labels t;

ALTER TABLE common_goods.fund_objectives_strategy_with_labels
MODIFY last_entry INT;