python-tutorial/03_basics/04_tuple.py at master · devopsor/python-tutorial

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###################################tuple########################################

# Another type of ordered list is called a tuple.

# Tuple and list are very similar, but once tuple is initialized, it cannot be modified. (※)

# For example, it also lists the names of classmates:

classmates = ('Michael', 'Bob', 'Tracy')

print(classmates[1]) #Bob

print(classmates) #('Michael', 'Bob', 'Tracy')

# Now, the tuple of classmates cannot be changed,

# nor does it have methods such as append() and insert().

# Other methods of getting elements are the same as list,

# you can use it normally classmates[0], classmates[-1] but you cannot assign it to another element.

# What's the point of an immutable tuple? Because tuples are immutable, the code is safer.

# If possible, use tuple instead of list.

# The trap of tuple: When you define a tuple, the elements of the tuple must be determined

# at the time of definition, such as:

t = (1, 2)

print(t) #(1, 2)

# If you want to define an empty tuple, you can write ():

t = ()

print(t) #()

# However, to define a tuple with only 1 element, if you define it like this:

t = (1)

print(t) #1

# The definition is not tuple, but 1, the number!

# This is because parentheses () can represent both tuple and parentheses in mathematical formulas,

# which creates ambiguity. Therefore, Python stipulates that the calculation results are naturally obtained

# according to the parentheses 1.

# Therefore, a tuple with only one element must be defined with a comma ,to disambiguate like the following:

t=(1,)

print(t) #(1,)

# When Python displays a tuple with only one element, it will also add a comma ,,

# so as not to be misunderstood as parentheses in the sense of mathematical calculations.

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