python pandas dataframe 我想创建一个函数来返回一个数据帧,这个数据框是经过筛选的数据帧,只包含由我的列表good_columns指定的列。 def filter_by_columns(data,columns): data = data[[good_columns]] #this is running an error when calling for my next line for: filter_data = fileter_by_columns(dat...
columns_ab = df.loc[:, ['A', 'B']] # 使用.iloc[]选择器 column_first = df.iloc[:, 0] # 第一列 columns_first_two = df.iloc[:, :2] # 前两列 参考文档:Python Pandas 数据选择与过滤-CJavaPy 2)列的过滤 可以基于列名的过滤、基于条件的过滤、使用列表推导式和使用filter函数的方法进行...
import polars as pl import time # 读取 CSV 文件 start = time.time() df_pl = pl.read_csv('test_data.csv') load_time_pl = time.time() - start # 过滤操作 start = time.time() filtered_pl = df_pl.filter(pl.col('value1') > 50) filter_time_pl = time.time() - start # 分组...
df.filter(items=['Q1', 'Q2']) # 选择两列df.filter(regex='Q', axis=1) # 列名包含Q的列df.filter(regex='e$', axis=1) # 以e结尾的列df.filter(regex='1$', axis=0) # 正则,索引名以1结尾df.filter(like='2', axis=0) # 索引中有2的# 索引...
Given a Pandas DataFrame, we have to filter it by multiple columns. Submitted by Pranit Sharma, on June 23, 2022 Pandas is a special tool that allows us to perform complex manipulations of data effectively and efficiently. Inside pandas, we mostly deal with a dataset in the form of ...
In this article, I will explain pandas filter by index and how we can get a DataFrame containing only rows and columns that are specified with the function. and also explain how to filter usingitems,likeexpression.DataFrame.index.isin()is another way to filter the rows of a pandas DataFrame...
filter是另外一个独特的筛选功能。filter不筛选具体数据,而是筛选特定的行或列。它支持三种筛选方式: items:固定列名 regex:正则表达式 like:以及模糊查询 axis:控制是行index或列columns的查询 下面举例介绍下。 train.filter(items=['Age','Sex']) train.filter(regex='S',axis=1)#列名包含S的 ...
"""to do the same filter on the index instead of arbitrary column""" df.ix[s] 得到一定条件的列 代码语言:python 代码运行次数:0 运行 AI代码解释 """ display only certain columns, note it is a list inside the parans """ df[['A', 'B']] 丢弃掉包含无效数据的行 代码语言:python 代码...
# Using the dataframe we created for read_csvfilter1 = df["value"].isin([112])filter2 = df["time"].isin([1949.000000])df [filter1 & filter2] copy() Copy () 函数用于复制 Pandas 对象。当一个数据帧分配给另一个数据帧时,如果对其中一个数据帧...
})# another one to perform the filterdf[df['country']=='USA'] 但是您可以在一个步骤中定义数据帧并对其进行查询(内存会立即释放,因为您没有创建任何临时变量) # this is equivalent to the code above# and uses no intermediate variablespd.DataFrame({'name':['john','david','anna'],'country':...