回答此问题可获得 20 贡献值,回答如果被采纳可获得 50 分。
<p>我有一段Python代码,基本上可以简化为以下内容:</p>
<pre><code>import pandas as pd
months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
l = [1607.8, 1688.17, 1605.66, 1469.03, 1312.65, 1451.74, 1445.26, 1350.94, 1371.27, 1201.6, 1240.59, 1291.43]
# First, construct a empty DataFrame.
df = pd.DataFrame(columns = months, dtype=float)
# Then, keep adding rows to DataFrame given by list l.
df.<a href="https://www.cnpython.com/list/append" class="inner-link">append</a>([l])
print df
</code></pre>
<p>预期产量为:</p>
^{pr2}$
<p>但是我得到的是:</p>
<pre><code>Empty DataFrame
Columns: [Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec]
Index: []
</code></pre>
<p>如果我将<code>df.append([l])</code>替换为以下内容,那么对我来说一切正常。在</p>
<pre><code>df = pd.DataFrame([l], columns = months)
df.columns = months
</code></pre>
<p>我做错什么了?在</p>