Summary of learning python basic knowledge strings

In the process of learning basic Python tutorials, we will generally involve basic knowledge such as strings, lists, tuples, and dictionaries. Next, we will record the cases where we learned strings, lists, tuples, and dictionaries as follows:

1. String:

String is the most commonly used data type in Python. We can use quotes (' or ") to create strings. Creating a string is as simple as assigning a value to a variable. For example:

var1="Big data"
var2='openstack'
需要注意的是在python里面双引号（""）与单引号（''）表示的含义完全相同，并不会存在像Shell里面
单引号和双引号不一致的问题。

Operations involving strings:

1. String splicing

In some special cases we need to splice strings. You can use the + sign to achieve splicing. You need to pay attention to the following matters:

Strings in python are in C The language is embodied as a character array. Every time you create a string, you need to open up a continuous space in the memory. And once you need to modify the string, you need to open up space again. The evil + sign will be included every time it appears. Re-open a space from it, so use string concatenation as little as possible

Simple example:

#!/usr/bin/env python
#_*_coding:utf-8_*_
print('----***字符串格式化输出***----')
"""name= input("input your name:")
password=input("inpur your password：")
print("your name: %s \nyour password: %s" %(name,password))
"""
name= input("input your name:")
age= input("input your age:")
job= input("input your job:")
salary= input("input your salary:")
print('----***字符串格式化输出 字符串拼接法***----')
"""字符串拼接法万恶的字符串拼接：
python中的字符串在C语言中体现为是一个字符数组，每次创建字符串时候需要
在内存中开辟一块连续的空，并且一旦需要修改字符串的话，就需要再次开辟空间，
万恶的+号每出现一次就会在内从中重新开辟一块空间。 """
 
info='''  --- info  of '''  + name +  '''   ---
name:'''  + name +  '''
age:'''  + age +  '''
job:'''  + job +  '''
salary:'''  + salary +  '''
 
'''
print(info)

Output result:

----***字符串格式化输出***----
input your name:python
input your age:20
input your job:linux sa
input your salary:20000
----***字符串格式化输出 字符串拼接法***----
  --- info  of python   ---
name:python
age:20
job:linux sa
salary:20000
 
Process finished with exit code 0

From this, we can see a String concatenation is a method for formatting strings. Next, we will share other string formatting methods.

#!/usr/bin/env python
#_*_coding:utf-8_*_
print('----***字符串格式化输出***----')
name= input("input your name:")
age= input("input your age:")
job= input("input your job:")
salary= input("input your salary:")
print('----***字符串格式化输出***----')
#print('name: %s\nage: %d\njob: %s\nsalary:%s ' %(name,int(age),job,salary))
print("""
name: %s
age: %d
job: %s
salary:%s """ %(name,int(age),job,salary))
print('----***字符串格式化输出 format 可以不带参数但是适合参数比较少***----')

Execution results:

input your name:baidu
input your age:22
input your job:99
input your salary:44
----***字符串格式化输出***----
 
name: baidu
age: 22
job: 99
salary:44 
----***字符串格式化输出 format 可以不带参数但是适合参数比较少***----
 
Process finished with exit code 0

From this we can see the random input. Different contents such as numbers and letters are output normally, but age, etc. should be represented by integers. During the formatted output process, we can not only use %s but also %d and %f (string is %s; integer %d; floating point number %f).

In addition, there are other formats, such as

#!/usr/bin/env python
#_*_coding:utf-8_*_
#!/usr/bin/env python
#_*_coding:utf-8_*_
print('----***字符串格式化输出***----')
name= input("input your name:")
age= input("input your age:")
job= input("input your job:")
salary= input("input your salary:")
 
info3=""" -------******info of {_name}-------******
name:{_name}
age:{_age}
job:{_job}
salary:{_salary}
 
""".format(_name=name,
           _age=age,
           _job=job,
           _salary=salary)
print(info3)
 
info4=""" -------******info of {0} 该方式适合变量少的情况括号是花括号-------******
name:{0}
age:{1}
job:{2}
salary:{3}
 
""".format(name,age,job,salary
          )
print(info4)

Execution results:

input your name:linux
input your age:mysql DBA
input your job:mysql DBA
input your salary:30000
 -------******info of linux-------******
name:linux
age:mysql DBA
job:mysql DBA
salary:30000
 
 
 -------******info of linux 该方式适合变量少的情况括号是花括号-------******
name:linux
age:mysql DBA
job:mysql DBA
salary:30000
Process finished with exit code 0

Strings are the ones we use most every day. There is still a lot of knowledge about data types, which will be improved in the later semesters

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