def spliting(): print('-'*60) import math print(math.pi) # 3.141592653589793 print(math.sqrt(4)) # 2
import random print(random.randint(1,10)) print(random.choice([1,2,3,4]))
spliting() s = 'lux' print(s[-1]) # x print(s[len(s)-1]) # x print(s) # lux s = 'j'+ s[1:] print(s) # jux print(s.find("j")) # 0 or -1 s = s.replace('u','in') print(s) # jinx s = 'mk 111' print(s.split()) # ['mk', '111'] print(s.isalpha()) # salse print('yi'.isalpha()) # true s = 'a\nb\tc\r\nd' print(s)
spliting()
import re match = re.match('hello[ \t](.)world','hello python world') print(match.group(1)) # 'python ' match = re.match('/(.)/(.)/(.*)','/bin/home/localjack') print(match.groups()) # ('bin', 'home', 'localjack') print(match.group()) # /bin/home/localjack
spliting()
a = ['a','b','c'] print([a*2 for a in a]) # ['aa', 'bb', 'cc'] print([a+b for a in a for b in '123'])
['a1', 'a2', 'a3', 'b1', 'b2', 'b3', 'c1', 'c2', 'c3']
d = {'a':1,"b":2,"d":4,"c":3} print(list(d.keys())) # ['a', 'b', 'd', 'c']
for k in d: print(k,d[k])
for k in sorted(d):
print(k,d[k])
a = [3,4,6,1,2] print(a.sort()) print(a) a = [3,4,6,1,2] print(sorted(a))
for i in 'spam': print(i.upper())
x= 4 while x > 0: print('spam '*x) x-=1 #spam spam spam spam #spam spam spam #spam spam #spam
a = [a2 for a in [1,2,3]]
print(a) # [2, 4, 6]
a = []
for i in [1,2,3]:
a.append(i2)
print(a) # [2, 4, 6]
spliting()
f = open('text.txt','w') f.write('hello\n') f.write('world\n') f.close()
with open('text.txt','w') as f: f.write('first bolood\n') f.write('jinx\n')
f = open('text.txt') f = f.read() print(f.split()) # ['first', 'bolood', 'jinx']
x = set('spam') y = set('xayz') print(x & y) # {'a'} print(x | y) # {'p', 'y', 'm', 'x', 'z', 's', 'a'} print(x-y) # {'s', 'm', 'p'}
for i in range(1,6): for j in range(1,6): if i >= j: print('*',end = '') else: print(' ',end = '') print()
spliting()
import decimal print(3.141+1) print(1/3) print((2/3)+(1/2)) d = decimal.Decimal('3.141') print(d+1) a = decimal.Decimal('1.00') / decimal.Decimal('3.00') print(a) # 0.3333333333333333333333333333 decimal.getcontext().prec = 2 a = decimal.Decimal('1.00') / decimal.Decimal('3.00') print(a) # 0.33 print(0.1+0.1+0.1) # 0.30000000000000004 decimal.getcontext().prec = 1 a = decimal.Decimal(0.1)+decimal.Decimal(0.1)+decimal.Decimal(0.1) print(a) # 0.3
decimal.getcontext().prec 可以设置decimal小数的精度 实现小数的精确计算
spliting()
from fractions import Fraction
f = Fraction(2,3) print(f+1) # 5/3 print(f + Fraction(1/2)) # 7/6
fractions 中的 Fraction可以实现分数的计算
spliting()
print(bool('bb')) # True print(bool( )) # False
print(type([1])) # <class 'list'> print(type(type))
spliting()
if type([1]) == type([]): print('yes') if type([1]) == list: print('yes') if isinstance([1],list): print('yes')
class Worker: def init(self,name,pay): self.name = name self.pay = pay def lastName(self): return self.name.split()[-1] def giveRaise(self,precent): self.pay *= (1.0 + precent) bob = Worker('Bob Smith', 50000) sue = Worker('Sue Jones', 60000) print(bob.lastName()) print(sue.lastName()) sue.giveRaise(.10) print(sue.pay)
