擅长:python、mysql、java
<p>您可以使用<code>.loc</code>来设置值。我假设<code>Balance1</code>是您要添加的新列</p>
<pre><code>#pop selected row of the balance 1 to 0
df.loc[(df['PaymentDate']) < datetime.date(2018, 9, 30)) & (df['Balance'] == df['Charge Amount']), 'Balance1'] = 0
#pop NaN row of the balance 1 to balance
df.loc[np.isnan(df['Balance1']), 'Balance1'] = df[np.isnan(df['Balance1'])]['Balance']
</code></pre>