String
def func_string():
str1 = "abcdefg"
print str1 #输出:abcdefg
print str1[1:3] #输出:bc
floatStr = "32.123456789"
print float(floatStr), int("32") #输出:32.123456789 32
print float('%0.3f' % 32.123456789) #输出:32.123
print "%0.3e"%0.123456789 # 输出:1.235e-01
字符串与进制之间的转换
def func_number():
print "=======十进制转换为其他进制========"
x = "16"
print "转换为十进制:", int(x)
print "十进制转换为二进制:", bin(int(x))
print "十进制转换为二进制:", DecToBin(int(x))
print "十进制转换为八进制:", oct(int(x))
print "十进制转换为十六进制:", hex(int(x))
print "=======其他进制转换为十进制========"
xStr = "101"
print "二进制转换为十进制:", int(xStr, base=2)
print "八进制转换为十进制:", int(xStr, base=8)
print "十六进制转换为十进制:", int(xStr, base=16)
def DecToBin(num):
'''
十进制转换为二进制 具体实现:
# /(传统除法) //(浮点除法,结果四舍五入)
'''
result = ''
if num:
result = DecToBin(num // 2)
return result + str(num % 2)
else:
return result
列表循环(元组可类比)
aList = [1, 2, “cdef”]
- 方法一:
for i in aList:
print i
- 方法二:根据索引遍历
for i in range(len(aList)):
print i, ':', aList[i]
- 方法三:枚举
for key,val in enumerate(aList):
print key, ':', val
- 方法四:迭代器
for i in iter(aList):
print i
字典循环
字典赋值:
方法一:
aDict = {'host': 'earth'}
aDict['port'] = 8080
方法二:
bDict = {"a": "apple", "b": "banana", "o": "orange"}
- 字典循环法一:
for key in bDict:
print key, bDict[key]
- 字典循环法二:
for k, v in bDict.items():
print k, v
- 字典循环法三:iteritems()返回值不是列表,而是一个迭代器
for k, v in dict.iteritems(bDict):
print k, v
- 字典循环法四:zip() 返回的是一个对象
for k, v in zip(bDict.keys(), bDict.values()):
print k, v
range()经常和len()一起用于字符串索引
foo = 'abcd'
for i in range(len(foo)):
print foo[i], '(%d)' % i