Question

我有一个数组，

months=['January','February','March','April','May','June','July','August','September','October','November','December']

我希望像

这样的字典

months = {1:'January', 2:'February',....}

我试过enumerate()但没有运气。如何为列表分配序列号到列表？提前谢谢！

Answer 1

由于dict()构造函数直接从键值对构建字典，因此也可以：

dict(enumerate(months, 1))

以下是一些测试，即使这对您的用例并不重要：

timeit dict(enumerate(months, 1))
The slowest run took 10.34 times longer than the fastest. This could mean that an intermediate result is being cached 
1000000 loops, best of 3: 1.37 µs per loop

timeit {i:m for i,m in enumerate(months,1)}
The slowest run took 7.77 times longer than the fastest. This could mean that an intermediate result is being cached 
1000000 loops, best of 3: 1.28 µs per loop

timeit {i+1:months[i] for i in range(12)}
The slowest run took 5.42 times longer than the fastest. This could mean that an intermediate result is being cached 
1000000 loops, best of 3: 1.89 µs per loop

Answer 2

试试这个。

months=
['January','February','March','April','May','June','July','August','September','October','November','December']

dict = {i+1:months[i] for i in range(12)}

正如评论中所指出的，使用范围（len（月））。由于在这种情况下已知列表的长度，我使用了12。

Answer 3

尝试使用此类eumerate强制它以1开头。

months =['January','February','March','April','May','June','July','August','September','October','November','December']
months = {i:m for i,m in enumerate(months,1)}
print months

将产生

{1: 'January', 2: 'February', 3: 'March', 4: 'April', 5: 'May', 6: 'June', 7: 'July', 8: 'August', 9: 'September', 10: 'October', 11: 'November', 12: 'December'}

Answer 4

如果你想坚持枚举，你可以这样做：

bias_palette <- colorRampPalette(c("blue", "magenta", "red", "yellow", "white"), bias=2, space="Lab")
spatstat::plot.im(k, col=bias_palette(256), ribbon = FALSE)

输出：

months =['January','February','March','April','May','June','July','August','September','October','November','December']

d_months = {}

for i, month in enumerate(months):
    d_months[i+1] = month

print(d_months)

由于枚举从0开始，您需要使用{1: 'January', 2: 'February', 3: 'March', 4: 'April', 5: 'May', 6: 'June', 7: 'July', 8: 'August', 9: 'September', 10: 'October', 11: 'November', 12: 'December'}

Answer 5

请试试这个

{i:months[i] for i in range(len(months))}

如何在python3中创建字典？

5 个答案: