List the List

A list in Python is an array of variable length, which I prefer to compare to a List in Java. The underlying implementation of an ArrayList in Java is an array, which is copied by adding () and removing () once it reaches its capacity.

Increased 1.

strings=["a"."b"."c"]
strings.append("d")
strings.insert(0."s")
print(strings)
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Results:

['s'.'a'.'b'.'c'.'d']
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2. Delete

Delete by index:

strings=["a"."b"."c"]
del strings[0]
print("del()".center(20."-"))
print(strings)
strings1=["a"."b"."c"]
a=strings1.pop()
print("pop()".center(20."-"))
print(a)
print(strings1)
strings2=["a"."b"."c"]
b=strings2.pop(1)
print("pop(index)".center(20."-"))
print(b)
print(strings2)
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The results of

-------del() -- -- -- -- -- -- -- -'b'.'c']
-------pop()--------
c
['a'.'b']
-----pop(index)-----
b
['a'.'c']
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Pop () if you want to delete the returned value, del() otherwise.

According to the value delete

strings=["a"."b"."c"]
strings.remove("c")
print(strings)
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['a', 'b']
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3. Change

If you know the index of the value that needs to be modified in the list:

strings=["a"."b"."c"]
strings[0] ="s"
print(strings)
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['s'.'b'.'c']
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If the value is known:

strings=["a"."b"."c"]
strings[strings.index("b")] ="s"
print(strings)
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['a'.'s'.'c']
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4. Check

slice

strings=["a"."d"."s"."h"]
print(strings[1:3])
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The results of

['d'.'s']
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The sorting

strings=["a"."d"."s"."h"]
Sort by first letter
strings.sort()
print("sort()".center(20."-"))
print(strings)
strings1=["a"."d"."s"."h"]
Sort by reverse alphabetic
strings1.sort(reverse=True)
print("sort(reverse)".center(20."-"))
print(strings1)
strings2=["a"."d"."s"."h"]
# temporary sort by first letter, do not change the list order
print("sorted".center(20."-"))
print(sorted(strings2))
print(strings2)
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The results of

-------sort()-------
['a'.'d'.'h'.'s']
---sort(reverse)----
['s'.'h'.'d'.'a'-- -- -- -- -- -- --sorted() -- -- -- -- -- -- -'a'.'d'.'h'.'s']
['a'.'d'.'s'.'h']
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traverse

Note that Python determines the relationship between line code and uplink code based on indentation;

strings=["a"."b"."c"."d"]
for string in  strings:
    print(string.title())
print("ssr")
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A
B
C
D
ssr
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Clever use of range()

# Print out 1-100
for num in range(1.101) :print(num)
Print an even number from 1 to 100
print(list(range(0.101.2)))
Take the sum of even numbers in 100
print(sum(list(range(0.101.2))))
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The results of

2550
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I have to say that if I were Java I would probably go through it and decide what’s divisible by 2 and put it in a variable. Python is very convenient.

Parse the list using for

squares1=[1.3.5.7.9]
squares2=[v**3 for v in squares1]
print(squares2)

squares3=[value**2 for value in range(1.11)]
print(squares3)
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Results:

[1.27.125.343.729]
[1.4.9.16.25.36.49.64.81.100]
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