Common functions for math in python
math.float(), converted to the largest integer less than or equal to this number "is used less", because int can be used
引入的三种方法：
import math
math.sqrt()
import matplotlib as plt
plt.plot()
from math import sin,pi
sin()
cos()list in python
Lists in Python can store any type of data, and the __ data types in the same list can also be different __;
lists are sequence structures, which can perform basic operations on sequence structures: indexing, slicing, adding, multiplying, and checking members.
1.mkdir
l = [1024,0.5,'python']
2.cd
l = [1024,0.5,'python']
print('l[0] --> ',l[0])
print('l[ 1:] --> ',l[1:])
The function in the list
1.append() "Add a new element to the list"
l = [1024, 0.5, 'Python']
# Modify the second element in the list
l[1] = 5
# add a new element to the list
l.append('Hello')
print('l[1] -->', l[1])
print('l -->', l)
result :
l[1] --> 5
l --> [1024, 5, 'Python', 'Hello']
2.del() "delete the element in the list"
l = [1024,0.5,'python']
#delete The second element
del l[1]
print('
3. Common methods:
1.count()
counts the number of occurrences of an element in the list
l = ['a','b','v','c','b']
print('l.count(b ) --> ',l.count('b')) #Output
result
l.count(b) --> 2
2.index()
Find the position where an element first appears in the list (ie index)
l = ['a','b','v','c','b']
print("l.index('b') --> ",l.index('b')) #Output
l
. index('b') --> 1
"Just look for the first one"
3.remove()
l = ['a','b','v','c','b']
l.remove( 'b')
print('l --> ',l)
#Output
l --> ['a', 'v', 'c', 'b'] "Only the first delete"
4.sort()
l = ['a','b','v','c','b']
l.sort()
print('l --> ',l)
#output
l --> [' a', 'b', 'b', 'c', 'v']
5.copy()
copy list
l = ['a','b','v','c','b']
lc = l.copy()
print('lc --> ',lc)
#输出
lc --> ['a', 'b', 'v', 'c', 'b']
Tuples in Python
A tuple is similar to a list, but a tuple is immutable and can be simply regarded as an immutable list. Tuples are often used to store unmodifiable content.
1.mkdir
t = (1024, 0.5, 'Python')
print('t[0] -->', t[0])
print('t[1:] -->', t[1:])
#Output result:
t[0] --> 1024
t[1:] --> (0.5, 'Python')
2. Modify "The elements in the tuple cannot be modified, we have to operate by reassignment"
t = (1024, 0.5, 'Python')
t = (1024, 0.5, 'Python', 'Hello')
print('t -->', t)
#Output result:
t --> (1024, 0.5, 'Python' ', 'Hello')
3. Delete "elements in a tuple cannot be deleted, we can only delete the entire tuple"
t = (1024, 0.5, 'Python')
del t
print('t --> ',t ) #Output
result
NameError: name 't' is not defined
Common method len()
1.
print('lens --> ',lens)
lens --> 3
2.max() and min()
t = ('d', 'b', 'a', 'f', 'd')
print('max(t) -->', max (t))
print('min(t) -->', min(t))
output the result
max(t) --> f
min(t) --> a
3.tuple() "Convert the list to the element Group"
t = ['d', 'b', 'a', 'f', 'd']
l = tuple(t)
print('l --> ',l)
#output result
l --> ( 'd', 'b', 'a', 'f', 'd')
Python draw a square
import turtle as t
t.fd(100)
t.left(90)
t.fd(100)
t.left(90)
t.fd(100)
t.left(90)
t.fd(100)Reference article:
Python Basics (1): Essential Knowledge for Getting Started - Programmer Sought