Checking if an index exists in a Python list is a common task to ensure that the index is within the acceptable range before trying to modify or access an element. Python lists are zero-indexed, meaning the first element is at index0, the second at index1, and so on. ...
# newwordlist = [] for index, x in enumerate(wordlist): # ['H', 'E', 'L', 'L', 'O'] if x in newwordlist or x == guessedletter: #just replace the value in the newwordlist newwordlist[index] = x #blow elif is not required # elif x not in newwordlist or x != g...
如果没找到,返回 -1 """ 91 """ 92 S.find(sub [,start [,end]]) -> int 93 94 Return the lowest index in S where substring sub is found, 95 such that sub is contained within S[start:end].
print(list1[4]) # 100 # print(list1[5]) # IndexError: list index out of range print(list1[-1]) # 100 print(list1[-3]) # 5 list1[2] = 300 print(list1) # [1, 3, 300, 7, 100] # 通过循环用下标遍历列表元素 for index in range(len(list1)): print(list1[index]) # ...
Python中的if函数是一种条件语句,用于根据条件的真假来决定程序的执行路径。它的基本语法如下: if 条件: 执行语句块 elif 条件: 执行语句块 else: 执行语句块 在这个语法中,if后面的条件可以是任何返回布尔值的表达式。如果条件为真,就会执行紧随其后的语句块。如果条件为假,程序将跳过该语句块并继续执行下一个语...
ifindex==1anditem=="人":print("耶斯莫拉!") #字符串的比较'''==,主要比较的是内容和具体的数据类型 in比较的是内容包含,也暗含了数据类型的比较包含,也暗含了数据类型的比较,因为比较首先前提是数据类型是一致的 is是比较两个对象的内存地址'''#前提:相同类型s1="hello world"s2="hello world"ifs1==...
songs = ['爱转角',"晴天",'人来人往','左手指月']foreachinsongs:print("正在播放歌曲:{}".format(each))"""正在播放歌曲:爱转角 正在播放歌曲:晴天 正在播放歌曲:人来人往 正在播放歌曲:左手指月""" 列表的切片 字符串的for循环 my_list = ['hello','love','python','lemon']foriinmy_list[1...
col_name = df.columns.tolist() col_name.insert(col_name.index("技能")+1,"技能类型") df = df.reindex(columns=col_name) def tech(x): if x.find("剑") >=0: a = "剑法" elif x.find("刀")>=0: a = "刀法" else: a = "其他" ...
Check if an element exists in a list in Python by leveraging various efficient methods, each suited to different scenarios and requirements. This article will guide you through the multitude of ways to determine the presence of an element within a list, ranging from the straightforward in operator...
D:\Anaconda3\python.exe D:/PycharmProjects/pythonz/day1/boke.py h e l l o 遍历序列类型: name_list=['hu','jin','xie','xu'] for i in name_list : #通过序列迭代 print(i) print('\n') for i in range(len(name_list)) : #通过索引迭代 print('index is %s,name is %s'%(i+...