关键字中的Python
在编程中,关键字是语言的“保留字”,它向解释器传达特殊含义。它可以是命令或参数。关键字不能用作程序片段中的变量名。 Python语言还保留了一些传达特殊含义的关键字。在Python中,关键字区分大小写。
“在”关键字:
in 关键字有两个用途:
- 检查列表、元组、范围、字符串等中是否存在值。
- 在 for 循环中遍历一个序列。
句法:
# Using if statement
if ele in seq:
statement(s)
# Using for statement
for ele in seq:
statement(s)
示例 1:
Python3
# Python program to demonstrate
# in keyword
# Create a list
animals = ["dog", "lion", "cat"]
# Check if lion in list or not
if "lion" in animals:
print("Yes")
Python3
# Python program to demonstrate
# in keyword
# Create a string
s = "GeeksforGeeks"
# Iterating through the string
for i in s:
# if f occurs in the string
# break the loop
if i == 'f':
break
print(i)
输出:
Yes
示例 2:
Python3
# Python program to demonstrate
# in keyword
# Create a string
s = "GeeksforGeeks"
# Iterating through the string
for i in s:
# if f occurs in the string
# break the loop
if i == 'f':
break
print(i)
输出:
G
e
e
k
s