Python 自动化指南(繁琐工作自动化)第二版:六、字符串操作 https://automatetheboringstuff.com/2e/chapter6/+操作符将两个字符串值连接在一起,但是您可以做得更多。您可以从字符串值中提取部分字符串,添加或删除空格,将字母转换为小写或大写,并检查字符串的格式是否正确。您甚至可以编写Python代码来访问剪贴板,以...
import textwrapwrapper = textwrap.TextWrapper(width=20, break_long_words=True)text = "Thisisaverylongwordthatwillbebrokenintomultiplelineswhentextiswrapped."wrapped_text = wrapper.wrap(text)for line in wrapped_text: print(line)输出：Thisisaverylongwordthatwillbebrokenintomultiplelineswhentextiswrap...
l = [1, 2, 3, 4] l[3] = 40 # 和很多语言类似,python中索引同样从0开始,l[3]表示访问列表的第四个元素 l [1, 2, 3, 40] tup = (1, 2, 3, 4) tup[3] = 40 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'tuple' object does not sup...
importstring# load doc into memorydefload_doc(filename):# open the file as read onlyfile = open(filename,'r')# read all texttext = file.read()# close the filefile.close()returntext# extract descriptions for imagesdefload_descriptions(doc):mapping = dict()# process linesforlineindoc.sp...
Feel free to take a break from this tutorial to practice everything that you’ve learned.In the second part of this tutorial, you’ll explore more advanced features, including how to do the following:Add decorators to classes Add several decorators to one function Create decorators with ...
break print('Passwords can only have letters and numbers.') 在第一个while循环中,我们询问用户的年龄,并将他们的输入存储在age中。如果age是一个有效的(十进制)值,我们就跳出第一个while循环,进入第二个循环,要求输入密码。否则,我们会通知用户需要输入一个数字,并再次要求他们输入年龄。在第二个while循环中...
1 # 循环的时候是在重复执行循环体里面的东西 2 # 在循环体里面遇到break,立即结束循环,不管循环有没有完 3 # 在循环体里面遇到continue,那么就结束本次循环,继续进行下一次循环 4 # while循环对应一个else时,循环正常结束之后才会执行它 5 import random 6 num = random.randint(1,100) # 随机产生一个1-...
>>> 1 / 0 Traceback (most recent call last): File "<stdin>", line 1, in <module> ZeroDivisionError: division by zero >>> one_more_func() Iteration 0💡 Explanation:When a return, break or continue statement is executed in the try suite of a "try…finally" statement, the finally...
False|class|return|is|finally|None|if|for|lamda|continue|True|def|from|while|nonlocal|and|del|global|not|with|as|elif|try|or|yield|assert|else|import|pass|break|except|in|raise Sentence or Lines 句子或行 When I move from words to sentences, you see that python is a series of lines. ...
break print str(i) i = i + 1 This while loop will run forever, because 1 is always true. Therefore, we will have to make sure there are conditions to break out of this loop; it will never stop on its own. Our first if statement checks to determine if the variable i is between ...