在Python中创建一个新的字典
我想用Python构建一本字典。 然而，我看到的所有例子都是从列表中实例化一个字典等。 ..
如何在Python中创建一个新的空字典？
调用没有参数的dict
new_dict = dict()
或者干脆写
new_dict = {}
你可以这样做
x = {}
x['a'] = 1
了解如何编写预设字典对于了解以下内容也很有用：
cmap = {'US':'USA','GB':'Great Britain'}
def cxlate(country):
try:
ret = cmap[country]
except:
ret = '?'
return ret
present = 'US' # this one is in the dict
missing = 'RU' # this one is not
print cxlate(present) # == USA
print cxlate(missing) # == ?
# or, much more simply as suggested below:
print cmap.get(present,'?') # == USA
print cmap.get(missing,'?') # == ?
# with country codes, you might prefer to return the original on failure:
print cmap.get(present,present) # == USA
print cmap.get(missing,missing) # == RU