http://www.pythontutor.com/visualize.html#mode=display
import math
def quadratic_equation(a, b, c):
x1=(-b+math.sqrt(b**2-4*a*c))/(2*a)
x2=(-b-math.sqrt(b**2-4*a*c))/(2*a)
return x1,x2
print quadratic_equation(2, 3, 0)
print quadratic_equation(1, -6, 5)
复制进去，点击生成可按步进方式观察函数运行的机制~
import math
def quadratic_equation(a, b, c):
x1=(-b+math.sqrt(b**2-4*a*c))/(2*a)
x2=(-b-math.sqrt(b**2-4*a*c))/(2*a)
return x1,x2
print quadratic_equation(2, 3, 0)
print quadratic_equation(1, -6, 5)
复制进去，点击生成可按步进方式观察函数运行的机制~
2016-10-21
AttributeError: 'dict' object has no attribute 'insert'
2016-10-21
# -*- coding: utf-8 -*-
print r'''
静夜思
床前明月光，
疑是地上霜。
举头望明月，
低头思故乡。'''
print r'''
静夜思
床前明月光，
疑是地上霜。
举头望明月，
低头思故乡。'''
2016-10-21
for x in range(1, 9):
for y in range(x + 1, 10):
print x * 10 + y
比
for x in [ 1,2,3,4,5,6,7,8,9 ]:
for y in [ 0,1,2,3,4,5,6,7,8,9 ]:
if x < y:
print x * 10 + y
好
for y in range(x + 1, 10):
print x * 10 + y
比
for x in [ 1,2,3,4,5,6,7,8,9 ]:
for y in [ 0,1,2,3,4,5,6,7,8,9 ]:
if x < y:
print x * 10 + y
好
2016-10-20
请问为什么多了s=答案就是错的？
s = set(['Adam', 'Lisa', 'Paul'])
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for name in L:
if name in s:
s=s.remove(name)
else:
s=s.add(name)
print s
s = set(['Adam', 'Lisa', 'Paul'])
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for name in L:
if name in s:
s=s.remove(name)
else:
s=s.add(name)
print s
2016-10-20