日列表功能、任务
split():
split() 方法根据分隔符将字符串划分为子字符串列表。
加入():
join() 方法使用调用它的字符串作为分隔符,将可迭代的元素连接成单个字符串。
使用循环的示例:
s = "today is thursday"reverse = ""i = 0while i<len(s): reverse = reverse + s[-(i+1)] i+=1print(reverse)i = 0 word = ""while i<len(reverse): if reverse[i]==' ': print(word[::-1],end=' ') word = "" i+=1 continue word = word + reverse[i] i+=1else: print(word[::-1])
yadsruht si yadotthursday is today
使用列表的示例:
sen = "today is thursday"l = sen.split(" ")print(l)print(l[::-1])s = " ".join(l[::-1])print(s)
['today', 'is', 'thursday']['thursday', 'is', 'today']thursday is today
深拷贝:
python 中的深拷贝是指创建一个新对象,该对象是原始对象的完全独立副本,包括嵌套在其中的所有对象。
l1 = [10,20,30]l2 = l1print(l1)print(id(l1))print(l2)print(id(l2))l2[0] = 111print(l1)print(l2)
[10, 20, 30]127285488814912[10, 20, 30]127285488814912[111, 20, 30][111, 20, 30]
浅复制:
浅拷贝,其中新对象是原始对象的副本,但它包含对相同嵌套对象的引用。
l1 = [10,20,30]l2 = l1.copy()print(l1)print(id(l1))print(l2)print(id(l2))l2[0] = 111print(l1)print(l2)
[10, 20, 30]140500496468800[10, 20, 30]140500496470528[10, 20, 30][111, 20, 30]
字典顺序:
词典顺序是单词在词典中按字母顺序排序的方式的概括。
l1 = ['lakshmi', 'guru', 'kuhan']l2 = ['lakshmi', 'guru', 'kuhan']print(l1 == l2)print(l1 != l2)l2 = ['guru', 'lakshmi', 'kuhan']print(l1>l2) print(l1<l2)
truefalsetruefalse
示例:
l1 = [10,20,30]l2 = [5,6,7]for no in l1: for num in l2: print(no, num, end=' ') print()
10 5 10 6 10 7 20 5 20 6 20 7 30 5 30 6 30 7
如果输出附近有 20 20,则删除:
l1 = [10,20,30]l2 = [8,20,7]for no in l1: for num in l2: if no==num: print(" ", end=" ") else: print(no, num, end=' ') print()
10 8 10 20 10 7 20 8 20 7 30 8 30 20 30 7
任务:
查找给定总和的对:5
l = [1,2,3,4,5,6,7,8,9,0]for i in range(len(l)): for j in range(len(l)): sum = l[i] + l[j] if sum == 5: print(l[i], l[j])
1 42 33 24 15 00 5
找到丢失的号码:
l = [10,20,30,50,60,70,80,90]i=0while i<len(l)-1: if l[i+1]-l[i]!=10: result=(l[i]+l[i+1])/2 print(int(result)) i+=1
40