擅长:python、mysql、java
<p>你应该试试<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.map.html" rel="nofollow noreferrer">^{<cd1>}</a>。它让它变得非常简单:</p>
<pre><code>import pandas as pd
# Loads csv1 with default index
df1 = pd.read_csv("csv1.csv")
# Loads csv2 and sets the year as the index
df2 = pd.read_csv("csv2.csv", index_col=0)
df1["zodiac"] = df1["year"].map(df2["zodiac"])
df1.to_csv("output.csv")
</code></pre>
<p>注意,<code>df2</code>的索引是年份,因此它的行为基本上与年号字典的行为类似。<code>map</code>接受字典或{<cd4>}作为列中值的查找表。在</p>