日志
pandas学习笔记，python数据科学手册
import pandas as pd
# series
# 带索引的一维数组
data = pd.Series([0.25,0.2,0.75,1.0])
print(data)
print("*"*60)
print(data.values)
print(data.index)
print(data[1])
print(data[1:3])
# 定义索引
data = pd.Series([0.25,0.2,0.75,1.0],
index=["a","b","c","d"])
print(data)
print(data["a"])
print("-"*60)
print(data.keys()) #字典方式查看索引
print(list(data.items())) #字典方式查看索引
data["e"] = 1 #增加数据
print(data)
# 切片
print("qiepiqna"*3)
print(data["a":"c"]) # 显示切片
print(data[0:2]) #前两行 # 隐示切片
print(data[(data > 0.3) & (data<0.8)])#掩码切片
print(data["a","e"]) #索引出来两个要素
# 字典方式创建
pp = {"a":12,
"b":55,
"c":4,
"d":11
}
pp = pd.Series(pp)
# 或者
pp = pd.Series({
"a":12,
"b":55,
"c":4,
"d":11
})
print(pp)
print(pp["b"])
# ------------------------
print("*"*60)
print("DataFrame")
# area
area_dict = {
"calforia":12121,
"floriad":54545,
"illsjf":89797,
"neww":85222,
"teass":45698
}
area = pd.Series(area_dict)
print(area)
#population
po_dict = {
"calforia":1,
"floriad":2,
"illsjf":3,
"neww":4,
"teass":5
}
population = pd.Series(po_dict)
print(population)
# dataframe
states = pd.DataFrame(
{"population":population,
"area":area}
)
print(states)
print(states.index)
print(states.columns)
print(states["area"])
# ----单个创建
dd = pd.DataFrame(population, columns=["population"])
print(dd)