pandas.DataFrameに列を追加(assign, contact)
import pandas as pd
import numpy as np
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%%html
<style>
table {float:left}
td {text-align:left}
</style>
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df = pd.DataFrame({'A': ['A1', 'A2', 'A3'],
'B': ['B1', 'B2', 'B3'],
'C': ['C1', 'C2', 'C3']},
index=['ONE', 'TWO', 'THREE'])
print(df)
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df['new column'] = [1, 2, 3]
print(df)
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df_new = df.assign(A=0)
print(df_new)
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df_new = df.assign(D=0)
print(df_new)
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s = pd.Series(['X2', 'X3', 'X4'], index=['TWO', 'THREE', 'FOUR'], name='X')
print(s)
df_new = df.assign(C='XXX',
D=0, E=[0, 1, 2],
F=s, G=s.values,
H=df['A'] + df['B'])
print(df_new)
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df = pd.DataFrame({'A': ['A1', 'A2', 'A3'],
'B': ['B1', 'B2', 'B3'],
'C': ['C1', 'C2', 'C3']},
index=['ONE', 'TWO', 'THREE'])
print(df)
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s = pd.Series(['X2', 'X3', 'X4'], index=['TWO', 'THREE', 'FOUR'], name='X')
print(s)
df_concat = pd.concat([df, s], axis=1, sort=True)
print(df_concat)
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df_concat_in = pd.concat([df, s], axis=1, join='inner')
print(df_concat_in)
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s1 = pd.Series(['X1', 'X2', 'X3'], index=df.index, name='X')
s2 = pd.Series(['Y1', 'Y2', 'Y3'], index=df.index, name='Y')
df_concat = pd.concat([df, s1, s2], axis=1)
print(df_concat)
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df2 = pd.DataFrame({'df_col1': 0, 'df_col2': range(3)}, index=df.index)
print(df2)
df_concat2 = pd.concat([df, df2], axis=1)
print(df_concat2)
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