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...
首先使用Polars CPU对数据集进行读取、过滤、分组聚合等处理。 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'...
代码如下：data.filter(regex="^[^B]+B[^B]+$",axis=1)1B11041526筛选列名以两个数字结尾的列...
dtype: datetime64[ns] In [566]: store.select_column("df_dc", "string") Out[566]: 0 foo 1 foo 2 foo 3 foo 4 NaN 5 NaN 6 foo 7 bar Name: string, dtype: object
df.filter(regex='Q', axis=1) # 列名包含Q的列 df.filter(regex='e$', 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 # 索引中以2开头、列名有Q的 ...
--Selecting a single rowwith.locwitha string--Age40Color White Food Apple Height80Score3.3StateALName:Penelope,dtype:object--Selecting multiple rowswith.locwitha listofstrings--Age Color Food Height Score State Cornelia39Red Beans1502.2TXJane30Blue Steak1654.6NYDean32Gray Cheese1801.8AK--Selecting ...
import ioimport requests# I am using this online data set just to make things easier foryou guysurl = "https://raw.github.com/vincentarelbundock/Rdatasets/master/csv/datasets/AirPassengers.csv"s = requests.get(url).content# read only first 10 rowsdf = pd.read_csv(io.StringIO(s.decode(...
.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...
# Getting first x rows. df.head(5) 1. 2. 我们只需要调用 head() 函数并且将想要查看的行数传入。 查看某列所有的值 df[column].unique() 1. 查看后 x 行的数据 # Getting last x rows. df.tail(5) 1. 2. 跟head 一样,我们只需要调用 tail 并且传入想要查看的行数即可。注意,它并不是从最...
import ioimport requests# I am using this online data set just to make things easier for you guysurl = "https://raw.github.com/vincentarelbundock/Rdatasets/master/csv/datasets/AirPassengers.csv"s = requests.get(url).content# read only first 10 rowsdf = pd.read_csv(io.StringIO(s....