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pandasからpolarsへの書き換え
CSVの読み込み
pandas
import pandas as pd
file_path = 'example.csv'
encoding = 'utf-8' # 文字コード
delimiter = ',' # デリミタ
df = pd.read_csv(file_path, encoding=encoding, delimiter=delimiter, error_bad_lines=False)
print(df)
polars
import polars as pl
file_path = 'example.csv'
encoding = 'utf-8' # 文字コード
delimiter = ',' # デリミタ
df = pl.read_csv(file_path, encoding=encoding, has_header=True, separator=delimiter, ignore_errors=True)
print(df)
データの絞り込み
pandas
import pandas as pd
data = {'A': [1, 2, 3], 'B': [4, 5, 6]}
df = pd.DataFrame(data)
result = df[df['A'] > 1]
print(result)
polars
import polars as pl
data = {'A': [1, 2, 3], 'B': [4, 5, 6]}
df = pl.DataFrame(data)
result = df.filter(df['A'] > 1)
print(result)
データのグルーピング
pandas
import pandas as pd
data = {
'Category': ['A', 'B', 'A', 'B', 'A'],
'Value': [10, 20, 15, 25, 5]
}
df = pd.DataFrame(data)
grouped = df.groupby('Category')['Value'].sum()
print(grouped)
polars
import polars as pl
data = {
'Category': ['A', 'B', 'A', 'B', 'A'],
'Value': [10, 20, 15, 25, 5]
}
df = pl.DataFrame(data)
grouped = df.groupby('Category').agg(pl.sum('Value').alias('TotalValue'))
print(grouped)
Dataframeを連想配列に変換
pandas
import pandas as pd
data = {
'Name': ['Alice', 'Bob', 'Charlie'],
'Age': [25, 30, 22]
}
df = pd.DataFrame(data)
list_of_records = df.to_dict(orient='records')
print(list_of_records)
polars
import polars as pl
data = {
'Name': ['Alice', 'Bob', 'Charlie'],
'Age': [25, 30, 22]
}
df = pl.DataFrame(data)
list_of_records = df.to_dicts()
print(list_of_records)