Catalog

One 、 Definition of tuple

Two 、 Tuples are commonly used

  3、 ... and 、 Loop traversal

Four 、 Application scenarios

One 、 Definition of tuple

Tuple（ Tuples ） Like a list , The difference is that the elements of a tuple cannot be modified

Tuples represent a sequence of elements , Tuples are in python In development , There are specific application scenarios , Used to store a string of information , Use... Between data , Separate

Tuple use （） Definition , The index of the tuple is from 0 Start , Index is the position number of data in tuple

info_tuple = ("zhangsan",18,1.75)

Create an empty tuple

tuple = ()

When a tuple contains only one element , Comma needs to be added after element

info_tuple = (50,)

The wrong sample ：

Two 、 Tuples are commonly used

stay ipython3 Define a tuple in , for example ：info = （）

Input info. Press down TAB key ,ipython The following functions can be used by tuples ：

info_tuple = ("zhangsan",18,1.75)
# 1. Value and index
print(info_tuple[0])
# Already know the content of data retrieval , Want to know the index of the data in the tuple
print(info_tuple.index("zhangsan"))
# 2. Statistics count
print(info_tuple.count("zhangsan"))
# Count the number of elements contained in the tuple
print(len(info_tuple))

  3、 ... and 、 Loop traversal

Value is to get the data stored in the specified location from the tuple

Traversal is to get data from tuples from beginning to end

info_tuple = ("zhangsan",18,1.75)
# Iterate through tuples
for my_info in info_tuple:
# Use format string splicing my_info This variable is inconvenient ！
# Because the data types usually stored in tuples are different ！
print(my_info)

stay python in , have access to for Loop through all variables of non numeric type ： list 、 Tuples 、 Dictionaries and strings

Tips ： In actual development , Unless you can confirm the data type in the tuple , Otherwise, there are not many loop traversal requirements for tuples

Four 、 Application scenarios

Although you can use for in Traversal tuples , But in development , More application scenarios are ：

Parameters and return values of functions , A function can take any number of parameters , Or return more than one data at a time

Format string , Format the... After the string （） It's essentially a tuple

Make the list non modifiable , To protect data security

# Format string , Format the... After the string （） It's essentially a tuple
# info = (" Xiao Ming ",18)
# print("%s The age of %d" % info)
print("%s The age of %d Height is %.2f" % (" Xiao Ming ",18,1.75))

info_str = "%s The age of %d Height is %.2f" % (" Xiao Ming ",18,1.75)
print(info_str)

Conversion between tuples and lists

Use list Function to convert tuples into lists

list( Tuples )

Use tuple Function to convert a list to a tuple

tuple( list )