擅长:python、mysql、java
<pre><code>import itertools
def comb_gen(iterable):
#Generate all combinations of items in iterable
for r in range(len(iterable)+1):
for i in itertools.combinations(iterable, r):
yield i
def upper_by_index(s, indexes):
#return a string which characters specified in indexes is uppered
return "".join(
i.upper() if index in indexes else i
for index, i in enumerate(s)
)
my_string = "abcd"
for i in comb_gen(range(len(my_string))):
print(upper_by_index(my_string, i))
</code></pre>
<p>输出:</p>
^{pr2}$