2016-07-01 93 views
0

我想以攝氏溫度拍攝一個CSV文件並將其轉換爲華氏度。CSV文件攝氏至華氏轉換

當前的嘗試:

import pandas as pd 
df = pd.read_csv('/temperature_data.csv',) 

def f(x): 
    x = x * 1.8 + 32 
    return float(x) 

df['AirTemperature'] = df.apply(f, axis=1) 

我可以,如果我只是輸入一個整數到功能成功地做到這一點,但我不斷收到此錯誤消息時,我嘗試使用CSV文件:

can't multiply sequence by non-int of type 'float' 

我試圖將值轉換爲浮動,但我沒有運氣。

編輯: 我使用的CSV文件是多列。它不僅僅是簡單的空氣溫度。

而且這裏充滿回溯

我沒有使用過熊貓
`--------------------------------------------------------------------------- 
TypeError         Traceback (most recent call last) 
<ipython-input-4-a63269740c5c> in <module>() 
----> 1 df['AirTemperature'] = df.apply(f, axis=1) 

/Users/pvayn/anaconda/lib/python2.7/site-packages/pandas/core/frame.pyc in apply(self, func, axis, broadcast, raw, reduce, args, **kwds) 
    4040      if reduce is None: 
    4041       reduce = True 
-> 4042      return self._apply_standard(f, axis, reduce=reduce) 
    4043    else: 
    4044     return self._apply_broadcast(f, axis) 

/Users/pvayn/anaconda/lib/python2.7/site-packages/pandas/core/frame.pyc in _apply_standard(self, func, axis, ignore_failures, reduce) 
    4136    try: 
    4137     for i, v in enumerate(series_gen): 
-> 4138      results[i] = func(v) 
    4139      keys.append(v.name) 
    4140    except Exception as e: 

<ipython-input-3-895f5da25595> in f(x) 
     1 def f(x): 
----> 2  x = x*1.8 + 32 
     3  return float(x) 

/Users/pvayn/anaconda/lib/python2.7/site-packages/pandas/core/ops.pyc in wrapper(left, right, name, na_op) 
    647     lvalues = lvalues.values 
    648 
--> 649    return left._constructor(wrap_results(na_op(lvalues, rvalues)), 
    650          index=left.index, name=left.name, 
    651          dtype=dtype) 

/Users/pvayn/anaconda/lib/python2.7/site-packages/pandas/core/ops.pyc in na_op(x, y) 
    588     result = np.empty(len(x), dtype=x.dtype) 
    589     mask = notnull(x) 
--> 590     result[mask] = op(x[mask], y) 
    591    else: 
    592     raise TypeError("{typ} cannot perform the operation " 

TypeError: ("can't multiply sequence by non-int of type 'float'", u'occurred at index 0') 
+0

您給出的代碼適用於我,包含浮點數和整數的單列CSV。我們能看到完整的追溯? –

+1

似乎很清楚,該函數收到的'x'是一個序列類型,而不是一個int。這似乎在文檔中提到:http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.apply.html您可能需要修改'f'來適應這一點。 –

+0

你有沒有建議我如何接近@DavidZemens? – pvayn

回答

1

但審查的文件,這看起來像它應該工作:

df['Air Temperature'] = df['Air Temperature'].apply(f) 

'Air Temperature'是在數據幀的一個系列,而series object也有應用方法。