1. Single quotation mark and escape Guide
2. Splicing string
3. Format string
4. Common methods
#Remove spaces and special symbols
#Search and replace strings
#String testing and replacement functions
#Segmentation of strings
#string module
#To create a string, you can use double quotes(" ")Or single quotes(' ')To create str1 = "hello" str2 = 'python' print(str1) print(type(str1))#See str1 Types
#String splicing, will str1 and str2 Concatenate into a new string str3 #Mode 1: use+To stitching together str3 = str1 + str2 print(str3) print(type(str3))
#The second way"join"To link strings str1 = "hello" str2 = "python" str3 = ','.join(str1 + str2)
print(str3) print(type(str3))
#If you want to print()Method to display multiple strings. You can use "," to split multiple strings a = "good" b = "good" c = "Study" print(a,b,c,"Make progress every day")
#print()Method will wrap after printing. In fact, he has a end Parameters, you can use"end="To remove line breaks str1 = "hello" str2 = "python" str3 = "My name is black" print(------Gorgeous dividing line------) print(str1, end='') print(str2, end='') print(str3)
#print When printing characters in multiple lines, the default is to separate them with a space. We can use sep To specify the split symbol name = "RCS" print("hello", name, sep='*-*')
#python Recommended later.format()To format a string #The first bracket accepts 1, the second 2, and the third (1+2) str1 = '{}+{}={}' .format(1,2,1 + 2) print(str1)
#If there is no data in parentheses, the default is to fill it from left to right #If there is mathematics in the brackets, it will be filled once according to the number position, here = 2 = 10 = 2/10 #python Like other languages, it's starting from scratch, not 1 str1 = '{}/{}={}' .format(10,2,10/2) str2 = '/=' .format(10,2,2/10) print(str1) print(str2)
#Alignment in formatting #<Align left no effect here .3f Represents to three decimal places str1 = '/=' .format(n1=10,n2=2,n3 =10 / 2) print(str1)
#Remove spaces and line breaks(/r) .strip()Method name = " Study hard, study every day" print("Before transformation:"， name) name = name.strip() print("After transformation:"， name)
#Remove a character name = "Study hard" print("Before transformation:"，name) name = name.strip("ah") print("After transformation:"，name)
#Remove left space name = " Study hard" print("Before transformation:",name) name = name.lstrip() print("After transformation:",name)
#Remove spaces and line breaks on the right name = "study hard " print("Before transformation:"， name) name = name.rstrip() print("After transformation:", name)
#Find the number of times a character appears in a string str1 = "black python" n = str1.count('n')#.count View the number of occurrences print('n There are:'， n, end='second')#end As mentioned earlier, specify what to end the output with
#Capitalize first name = black print("Before transformation:"， name) name = name.capitalize()#.capitalize Function is to capitalize the first letter print('After transformation:', name)
# Put the string in the middle and use it on both sides'-'Make up name = "Python Learning group" print("Before transformation:", name) name = name.center(20, '-') # 20 Refers to the length of the transformed string .conter Stands for putting characters in the middle'-'Can be replaced at will print("After transformation:", name)
#Find the position of the target character in the string, and return the first position when there are more than one #Can't find it back-1 name = "python Study" i = name.find('learn')#.find Query statement temp = '{}in{}First time in{}Position'.format(name,'learn',i)#Note that all symbols must be in English,
Otherwise, an error will be reported .format As mentioned earlier, it's a format string, which is equivalent to typesetting. One more thing to note, starting from zero print(temp)
#String substitution name = "I am learning. java" print("Before transformation:", name) name = name.replace('java', 'Python') print("After transformation:", name)
#See if the strings are all letters or text and have at least one character name = 'abcdef' name2 = 'python2 Study' print(name.isalpha())#isalpha A function: judging characters ch English letters or not print(name2.isalpha())
#See if it's all numbers name = '12345' name2 = 'abc123' print(name.isdigit()) print(name2.isdigit())#isdigit Function to determine whether it is a number
#See if they are all lowercase islower() Capitalization issupper() name = 'abc123' print(name.islower()) print(name.supper())
