Series的基本功能.ipynb

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       "'\\nPandas基本功能:\\n    axes 返回行轴标签列表\\n    dtype 返回对象的数据类型\\n    empty 如果系列为空，则返回True\\n    ndim 返回底层数据的维数，默认为1\\n    size 返回基础数据中的元素数\\n    values 将系列作为ndarray返回\\n    head() 返回n行\\n    tail() 返回最后n行\\n'"
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   "source": [
    "'''\n",
    "Pandas.Series基本功能:\n",
    "    axes 返回行轴标签列表\n",
    "    dtype 返回对象的数据类型\n",
    "    empty 如果系列为空，则返回True\n",
    "    ndim 返回底层数据的维数，默认为1\n",
    "    size 返回基础数据中的元素数\n",
    "    values 将系列作为ndarray返回\n",
    "    head() 返回n行\n",
    "    tail() 返回最后n行\n",
    "'''"
   ]
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     "text": [
      "The axes are:\n",
      "[RangeIndex(start=0, stop=4, step=1)]\n"
     ]
    }
   ],
   "source": [
    "# axes 返回系列的标签列表\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 100 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (\"The axes are:\")\n",
    "print (s.axes) # 返回从0 到5 的值列表的紧凑格式，即[0,1,2,3,4]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
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     "text": [
      "Is the Object empty?\n",
      "False\n"
     ]
    }
   ],
   "source": [
    "# empty 返回布尔值，表示对象是否为空，返回True则表示对象为空\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 100 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (\"Is the Object empty?\")\n",
    "print (s.empty)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
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     "text": [
      "0    0.992125\n",
      "1    0.267084\n",
      "2    0.904634\n",
      "3   -0.304343\n",
      "dtype: float64\n",
      "The dimensions of the object:\n",
      "1\n"
     ]
    }
   ],
   "source": [
    "# ndim 返回对象的维数 ，根据定义，一个序列是一个1D数据结构\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 4 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (s)\n",
    "\n",
    "print (\"The dimensions of the object:\")\n",
    "print (s.ndim)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
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     "text": [
      "0    1.328609\n",
      "1   -1.839106\n",
      "dtype: float64\n",
      "The size of the object:\n",
      "2\n"
     ]
    }
   ],
   "source": [
    "# size 返回系列的大小(长度)\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 4 random numbers\n",
    "s = pd.Series(np.random.randn(2))\n",
    "print (s)\n",
    "print (\"The size of the object:\")\n",
    "print (s.size)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "0    0.483418\n",
      "1   -0.220665\n",
      "2   -0.017396\n",
      "3    0.535343\n",
      "dtype: float64\n",
      "The actual data series is:\n",
      "[ 0.48341788 -0.22066507 -0.01739587  0.53534257]\n"
     ]
    }
   ],
   "source": [
    "# values 以数组的形式返回系列中的实际数据值\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 4 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (s)\n",
    "\n",
    "print (\"The actual data series is:\")\n",
    "print (s.values)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
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     "text": [
      "The original series is:\n",
      "0   -0.443913\n",
      "1    1.567744\n",
      "2   -0.144442\n",
      "3    0.284433\n",
      "dtype: float64\n",
      "The first two rows of the data series:\n",
      "0   -0.443913\n",
      "1    1.567744\n",
      "dtype: float64\n"
     ]
    }
   ],
   "source": [
    "# head() 可以查看Series或DataFrame对象的小样本，返回前n行，其中默认值是5，但可以传递自定义这个数值\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 4 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (\"The original series is:\")\n",
    "print (s)\n",
    "\n",
    "print (\"The first two rows of the data series:\")\n",
    "print (s.head(2)) # 其中n=2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# tail() 返回最后n行，要显示的元素的默认数量为5，但是可以传递自定义数字值\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "#Create a series with 4 random numbers\n",
    "s = pd.Series(np.random.randn(4))\n",
    "print (\"The original series is:\")\n",
    "print (s)\n",
    "\n",
    "print (\"The last two rows of the data series:\")\n",
    "print (s.tail(2)) # 其中n=2"
   ]
  }
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