題目 :
列印出楊輝三角形前十行。
程式分析 無。
def
generate
(numrows)
: r =[[
1]]for i in
range(1
,numrows)
:list
(map
(lambda x,y:x+y,[0
]+r[-1
],r[-1
]+[0
])))
return r[
:numrows]
a=generate(10)
for i in a:
print
(i)
查詢字串。
程式分析 無。
s1=
'aabbxuebixuebi'
s2='ab'
s3='xue'
print
(s1.find(s2)
)print
(s1.find(s3)
)
程式分析 使用 tkinter。
if __name__ ==
'__main__'
:from tkinter import
* x =
360 y =
160 top = y -
30 bottom = y -
30
canvas = canvas(width =
400,height =
600,bg =
'white'
)for i in
range(20
):canvas.create_oval(
250- top,
250- bottom,
250+ top,
250+ bottom)
top -=
5 bottom +=
5 canvas.pack(
) mainloop(
)
程式分析 無。
if __name__ ==
'__main__'
:from tkinter import
* canvas = canvas(width =
400,height =
600,bg =
'white'
) left =
20 right =
50 top =
50 num =
15for i in
range
(num)
: canvas.create_oval(
250- right,
250- left,
250+ right,
250+ left)
canvas.create_oval(
250-20,
250- top,
250+20,
250+ top)
canvas.create_rectangle(20-
2* i,20-
2* i,10*
(i +2)
,10*( i +2)
) right +=
5 left +=
5 top +=
10 canvas.pack(
) mainloop(
)
程式分析 無。
import math
from tkinter import
*class
pts:
def__init__
(self)
: self.x =
0 self.y =
0points =
deflinetodemo()
: screenx =
400 screeny =
400 canvas = canvas(width = screenx,height = screeny,bg =
'white'
) aspectratio =
0.85
maxpts =
15 h = screeny
w = screenx
xcenter = w /
2 ycenter = h /
2 radius =
(h -30)
/(aspectratio *2)
-20step =
360/ maxpts
angle =
0.0for i in
range
(maxpts)
: rads = angle * math.pi /
180.0
p = pts(
) p.x = xcenter +
int(math.cos(rads)
* radius)
p.y = ycenter -
int(math.sin(rads)
* radius * aspectratio)
angle += step
canvas.create_oval(xcenter - radius,ycenter - radius,
xcenter + radius,ycenter + radius)
for i in
range
(maxpts)
:for j in
range
(i,maxpts)
: canvas.create_line(points[i]
.x,points[i]
.y,points[j]
.x,points[j]
.y) canvas.pack(
) mainloop(
)if __name__ ==
'__main__'
: linetodemo(
)
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