成员运算符
成员标识运算符是用于验证值的成员标识的运算符。它测试序列中的成员标识, 例如字符串, 列表或元组。
在in运算符中:” in”运算符用于检查一个值是否存在于序列中。如果找到指定序列中的变量, 则评估为true, 否则为false。
# Python program to illustrate
# Finding common member in list
# using 'in' operator
list1 = [ 1 , 2 , 3 , 4 , 5 ]
list2 = [ 6 , 7 , 8 , 9 ]
for item in list1:
if item in list2:
print ( "overlapping" )
else :
print ( "not overlapping" )
输出如下:
not overlapping
没有使用in运算符的相同示例:
# Python program to illustrate
# Finding common member in list
# without using 'in' operator
# Define a function() that takes two lists
def overlapping(list1, list2):
c = 0
d = 0
for i in list1:
c + = 1
for i in list2:
d + = 1
for i in range ( 0 , c):
for j in range ( 0 , d):
if (list1[i] = = list2[j]):
return 1
return 0
list1 = [ 1 , 2 , 3 , 4 , 5 ]
list2 = [ 6 , 7 , 8 , 9 ]
if (overlapping(list1, list2)):
print ( "overlapping" )
else :
print ( "not overlapping" )
输出如下:
not overlapping
“not in”运算符-
如果找不到指定序列中的变量, 则求值为true, 否则为false。
# Python program to illustrate
# not 'in' operator
x = 24
y = 20
list = [ 10 , 20 , 30 , 40 , 50 ];
if ( x not in list ):
print ( "x is NOT present in given list" )
else :
print ( "x is present in given list" )
if ( y in list ):
print ( "y is present in given list" )
else :
print ( "y is NOT present in given list" )
标识运算符
在Python中, 用于确定值是特定类还是类型。它们通常用于确定某个变量包含的数据类型。
有不同的标识运算符, 例如
“is”运算符–
如果运算符两侧的变量指向同一对象, 则计算为true, 否则为false。
# Python program to illustrate the use
# of 'is' identity operator
x = 5
if ( type (x) is int ):
print ( "true" )
else :
print ( "false" )
输出如下:
true
“is not”运算符–
如果运算符两侧的变量指向同一个对象, 则结果为false, 否则为true。
# Python program to illustrate the
# use of 'is not' identity operator
x = 5.2
if ( type (x) is not int ):
print ( "true" )
else :
print ( "false" )
输出如下:
true
首先, 你的面试准备可通过以下方式增强你的数据结构概念:Python DS课程。
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