假设我们正在解决一个简单的字数统计问题。有一个列表,我们正在尝试查找列表中出现的每个单词的字数。这里哪种模式更快?
book_title = ['great', 'expectations','the', 'adventures', 'of', 'sherlock','holmes','the','great','gasby','hamlet','adventures','of','huckleberry','fin']
word_count_dict = {}
Run Code Online (Sandbox Code Playgroud)
for word in book_title:
if word in word_count_dict:
word_count_dict[word] += 1
else:
word_count_dict[word] = 1
Run Code Online (Sandbox Code Playgroud)
for word in book_title:
if word not in word_counter:
word_counter[word] = 1
else:
word_counter[word] += 1
Run Code Online (Sandbox Code Playgroud) 我有一个包含三种节点类型的图:NodeX,NodeY和NodeZ
我有这个密码查询:
MATCH (x:NodeX)-[*]->(d)
WHERE x.Name = 'pqr'
RETURN x,d;
Run Code Online (Sandbox Code Playgroud)
这里(d)可以是NodeY或NodeZ.我想分别处理不同的nodetypes.就像是:
MATCH (x:NodeX)-[*]->(d)
WHERE x.Name = 'pqr'
WITH d
CASE WHEN typeof(d)=NodeY THEN {MATCH (y:NodeY)-[*]-(z:NodeZ)}
WHEN typeof(d)=NodeZ THEN {MATCH (z:NodeZ)-[*]-(y:NodeY)}
RETURN y,z
Run Code Online (Sandbox Code Playgroud)
y并z对应于d.这可能吗?