import pandas as pd

# 第一种数据类型 series 类似于一维数组，由一组数据和数据标签组成，默认从0开始

s1 = pd.Series(['a', 'b', 'c', 'd'])

print(s1)


print(s1[0])

# 或者自定义索引

s2 = pd.Series([1, 2, 3, 4], index=['a', 'b', 'c', 'd'])

print(s2)

print(s2['a'])

# 将字典转为series key值变为索引

dic = {'a': 'aaa', 'b': 'bbb', 'c': 'ccc'}

s3 = pd.Series(dic)

print(s3)

print(s3['a'])

# dataframe是一个表格型的数据类型，它含有不同的列，既有行索引也有列索引，类似一张excel表格或是SQL数据库表

# 二维列表转为dataframe
list=[[2,2,2,2],[3,3,3,3],[4,4,4,4],[5,5,5,5]]

df1=pd.DataFrame(list,index=['a','b','c','d'],columns=['A','B','C','D'])

print(df1)

#由字典组成的列表 
data = [{"one":1,"two":2},{"one":5,"two":10,"three":15}]
df1 = pd.DataFrame(data)
df2 = pd.DataFrame(data, index = ["a", "b"])
df3 = pd.DataFrame(data, columns = ["one", "two"])
df4 = pd.DataFrame(data, columns = ["one", "two", "three"])
df5 = pd.DataFrame(data, columns = ["one", "two", "three", "fff"])
print(df1)
print()
print(df2)
print()
print(df3)
print()
print(df4)
print()
print(df5)
# 总结：由字典组成的列表创建Dataframe， columns（即列标签）为字典的key， index不做指定默认为数字标签