1.计算器实例
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#/usr/bin/env python
# -*- coding:utf-8 -*-
# @time :2018/1/22 21:09
# @Author :FengXiaoqing
# @file :jsq.py
def
add(string):
total
=
0
numbers
=
[]
numbers
+
=
string.split(
"+"
)
for
num
in
numbers:
total
+
=
int
(num.strip())
print
(
"{0} = {1}"
.
format
(string,total))
def
reduce
(string):
result
=
0
numbers
=
[]
numbers
+
=
string.split(
"-"
)
result
=
int
(numbers[
0
].strip())
numbers.pop(
0
)
for
num
in
numbers:
result
-
=
int
(num.strip())
print
(
"{0} = {1}"
.
format
(string,result))
def
ride(string):
total
=
1
numbers
=
[]
numbers
+
=
string.split(
"*"
)
for
num
in
numbers:
total
*
=
int
(num.strip())
print
(
"{0} = {1}"
.
format
(string, total))
def
division(string):
result
=
0
numbers
=
[]
numbers
+
=
string.split(
"/"
)
result
=
int
(numbers[
0
].strip())
numbers.pop(
0
)
for
num
in
numbers:
result
/
=
int
(num.strip())
print
(
"{0} = {1}"
.
format
(string, result))
if
__name__
=
=
'__main__'
:
print
(
"####################################################"
)
print
(
"##################欢迎来到计算中心##################"
)
print
(
"####################################################"
)
print
(
"1: 加法 a + b + c ..."
)
print
(
"2: 减法 a - b - c ..."
)
print
(
"3: 乘法 a * b * c ..."
)
print
(
"4: 除法 a / b / c ..."
)
method
=
input
(
"Please input number:1/2/3/4: "
)
if
method
=
=
"1"
:
string
=
input
(
"请输入表达式:"
)
add(string)
elif
method
=
=
"2"
:
string
=
input
(
"请输入表达式:"
)
reduce
(string)
elif
method
=
=
"3"
:
string
=
input
(
"请输入表达式:"
)
ride(string)
elif
method
=
=
"4"
:
string
=
input
(
"请输入表达式:"
)
division(string)
else
:
print
(
"Please input 1/2/3/4 ERROR"
)
|
2.tuple元组
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a1
=
(
1
)
a2
=
(
1
,)
print
(a1)
print
(a2)
|
结果:
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2
|
1
(
1
,)
|
Tuple 是单元素时候,一定要加"," 否则无法识别是tuple类型
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方法:
m
=
(
1
,
2
,
3
,
4
,
5
,
6
,
7
,
8
,
1
,
34
,
6
,
6
,
3
,
2
)
# 返回第一个value元素的下标;
print
(m.index(
3
))
#统计value元素的个数
print
(m.count(
6
))
|
结果:
1
2
|
2
3
|
3.dict字典
字典的定义(三种方式 ):
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d1
=
dict
(name
=
"fxq"
,age
=
20
)
d2
=
{
'name'
:
'fxq'
,
'age'
:
20
}
d3
=
dict
([(
'name'
,
'fxq'
),(
'age'
,
20
)])
print
(d1)
print
(d2)
print
(d3)
|
字典的常用方法:
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get(k) 返回K所对应的value
setdefault(k,v) 如果k不存在,设置一个默认值v,并返回v,如果k存在,返回k对应的value
keys() 获得所有的keys
values() 获得所有的values
iteritems()
for
i,j
in
d.iteritems():
print
(i,j)
update() m.update(n) m,n都是
dict
pop(k) 删除k:v 对应的元素
zip
(l1,l2) 高阶函数,
dict
(
zip
(l1,l2)) 把l1和l2转换成
mm
=
dict
(a
=
1
,b
=
10
,c
=
3
,d
=
9
)
print
sorted
(mm.iteritems(),key
=
lambda
d:d[
1
],reverse
=
True
)
|
4.其他常用操作
帮助信息:
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|
help
()
dir
()
|
方法:
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str
()
int
()
list
()
dict
()
tuple
()
xrange
()
range
()
iteritems()
items()
input
raw_input
len
()
type
()
isinstance
() 判断是什么类型,返回一个
bool
类型
a
=
123
print
(
isinstance
(a,
int
))
print
()
enumerate
()
|
字符串中方法:
find replace split join format startswith endswith
python 2 和3 中的区别:
python 2 print 支持 print s1,s2,s3 就是不回车在一行
python 3 print 包装成一个函数,print(s,end"") 不回车在一行
python 2 中 存在 xrange() range() d.iteritems() d.items
python 3 中只存在 range() items()
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本文转自 枫叶云 51CTO博客,原文链接:http://blog.51cto.com/fengyunshan911/2064014