1. for循环时,变量的初始化范围:
lenth = 8
for i in range(lenth): # i的范围是[0,8)
'''
processing module
'''
for i in range(1,lenth): # i的范围是[1,8)
'''
processing module
'''
2. list 初始化:
lenth = 8
listItem1 = [1]*lenth # 初始化一个元素都为1,大小为8的list
listItem2 = [None]*lenth # 初始化一个大小为8的空list
'''
a= [None]*8
a
Out[58]: [None, None, None, None, None, None, None, None]
b = [0]*8
b
Out[60]: [0, 0, 0, 0, 0, 0, 0, 0]
'''
3.list 插入:
listName.insert(pos,element)
'''
a
Out[68]: [None, None, None, None, None, None, None, None]
a.insert(1,3)
a
Out[70]: [None, 3, None, None, None, None, None, None, None]
'''
4.list的sort排序:
def cmpa(A):
return A[0],-A[1] # A[0]升序排列,A[1]降序排列
people.sort(key=cmpa)
'''
people = [[2,0],[1,4],[1,3],[0,8]]
people.sort(key = cmpa)
people
Out[79]: [[0, 8], [1, 4], [1, 3], [2, 0]]
'''
5. list 查找元素:
if element (not) in List # 查找元素是否存在
List.count(element) # 统计元素出现的次数
List.index(element) # 统计元素第一次出现的位置
6.中文显示乱码问题
plt.rcParams['font.sans-serif']=['SimHei'] #用来正常显示中文标签
plt.rcParams['axes.unicode_minus']=False #用来正常显示负号