擅长:python、mysql、java
<p>当您试图使用with语句时,您的意思是这样的-在这种情况下,文件将在其下留下代码后立即关闭:</p>
<pre><code>from csv import reader
def citypop():
D = {}
with open("Top5000Population.txt") as F:
for city, state, population in reader(F):
city = city.upper()[:12]
D[(city, state)] = int(population.replace(',',''))
return D
</code></pre>
<p>或者:</p>
^{pr2}$