In [1]:
import pandas as pd
cols = ['col1', 'col2']
df = pd.DataFrame(index=[], columns=cols)
record = pd.Series(['hoge', 'fuga'], index=df.columns)
for _ in range(5):
df = df.append(record, ignore_index=True)
print(df)
In [2]:
df_blank = df.iloc[0:0]
print(df_blank)
df1 = df_blank.append(df)
print(df1)
In [3]:
import pandas as pd
import numpy as np
# 元になるDataFrame
df = pd.DataFrame(np.random.random([100, 3]), columns=['foo', 'bar', 'baz'])
print(df.head())
print(len(df))
In [4]:
# カラムがないindexだけ設定されているDataFrameを作成
df_new = pd.DataFrame(index=df.index, columns=[])
print(df_new)
In [5]:
# これにdfを整形したカラムを追加してみる
df_new['hoge'] = df.foo ** 2
print(df_new.head())
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