Python列表生成式(入门9)

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http://www.cnblogs.com/why168888/p/6407984.html

本文出自:【Edwin博客园】

Python列表生成式

1. 生成列表

L = []
for x in range(1, 11):
	L.append(x * x)
print L

print '
'

print [x * x for x in range(1, 11)]

print '
'

print [x * (x + 1) for x in range(1, 100, 2)]

2. 复杂表达式

d = { 'Adam': 95, 'Lisa': 85, 'Bart': 59 }
tds = ['<tr><td>%s</td><td>%s</td></tr>' % (name, score) for name, score in d.iteritems()]
print '<table>'
print '<tr><th>Name</th><th>Score</th><tr>'
print '
'.join(tds)
print '</table>'

print '
'

d = { 'Adam': 95, 'Lisa': 85, 'Bart': 59 }
def generate_tr(name, score):
    if score < 60:
        return '<tr><td>%s</td><td style="color:red">%s</td></tr>' % (name, score)
    return '<tr><td>%s</td><td>%s</td></tr>' % (name, score)
tds = [generate_tr(name, score) for name, score in d.iteritems()]
print '<table border="1">'
print '<tr><th>Name</th><th>Score</th><tr>'
print '
'.join(tds)
print '</table>'

3. 条件过滤

print [x * x for x in range(1, 11)]

print '
'

print [x * x for x in range(1, 11) if x % 2 == 0]

print '
'

def toUppers(L):
    return [x.upper() for x in L if isinstance(x, str)]
print toUppers(['Hello', 'world', 101])

4. 多层表达式

print [m + n for m in 'ABC' for n in '123']

print '
'

L = []
for m in 'ABC':
    for n in '123':
        L.append(m + n)
print L

print '
'

print [100 * n1 + 10 * n2 + n3 for n1 in range(1, 10) for n2 in range(10) for n3 in range(10) if n1==n3]