The apply() method shows you how to create a new column in a Pandas based on condition. The apply() method takes a function as an argument and applies that function to each row in the DataFrame. The function you pass to the apply() method should return a single value. The function sh...
def delete_rows_based_on_condition(file_path, column_name, condition): df = pd.read_excel(file_path) df = df[df[column_name] != condition] # 删除满足条件的行 df.to_excel(file_path, index=False) delete_rows_based_on_condition('example.xlsx', '状态', '无效') print("符合条件的行...
upper_tri = train_factor_corr_ts_mean.where(np.triu(np.ones(train_factor_corr_ts_mean.shape), k=1).astype(np.bool)) selected = [column for column in upper_tri.columns if all(upper_tri[column].dropna() < corr_threshold)] X_df = X_df[selected] factor_check_df_selected = factor_...
def__init__(self,left:Field,operation:str,right:Any): self.condition=f'`{left.name}`{operation}"{right}"' def__or__(self,other:"Compare"): self.condition=f'({self.condition}) OR ({other.condition})' returnself def__and__(self,other:"Compare"): self.condition=f'({self.condition...
username = Column(String(length=25), unique=True, nullable=False) 在我们定义了所有的列之后,我们提供了__repr__方法的定义。__repr__方法是一个魔术方法,它由内部的repr()Python 方法调用,以提供对象的表示,比如当用户发出print(userobj)时。 这样就完成了我们使用 SQLAlchemy 定义用户模型的定义。很简单...
避免链式索引:如df[condition]['column'],应使用df.loc[condition, 'column'] 多层索引的合理使用:当数据有自然层次关系时使用 索引的性能考虑:索引可以加速查询,但会增加内存使用 # 不好的实践 - 链式索引# df[df['Age'] > 30]['Name']# 好的实践print(df.loc[df['Age']>30,'Name'])""" ...
在我们使用if column == \'0\'命令检查每一列是否有0之后,我们只将这样的位置存储到 positions 字典中,并从函数中返回。 当进行旋转和移动等操作时,用户可能会触发一些无效的移动,比如将对象旋转到网格外部。因此,我们必须检查这些无效的移动并阻止它们发生。我们将创建check_Moves()函数来实现这一点。这个函数的...
The second is a compound expression that combines the modulo (%) and equality (==) operators to create a condition that checks whether the input value is an even number. In this condition, the modulo operator returns the remainder of dividing number by 2, and the equality operator compares ...
create table if not exists table_name (column1, column2, …, columnN) For example: import sqlite3 con = sqlite3.connect('mydatabase.db') def sql_fetch(con): cursorObj = con.cursor() cursorObj.execute('create table if not exists projects(id integer, name text)') ...
Python开发常用组件、命令(干货) 1、生成6位数字随机验证码 import random import string def num_code(length=6): """ 生成长度为length的数字随机验证码 :param length: 验证码长度 :return: 验证码 """ return ''.join(random.choice(string.digits) for i in range(0, length)) ...