从CSV,将类似数据组合在一起?

时间:2018-02-16 22:44:33

标签: python python-3.x pandas csv dataframe

我有一些我想要组合在一起的数据:

Serial_Num     Latitude Longitude
1950004S11059   -11.1   59.1
1950004S11059   -11.6   57.8
1950004S11059   -12.4   56
1950004S11059   -13.2   54.6
1950004S11059   -13.8   53.8
1950004S11059   -14.8   52.7
1950004S11059   -15.9   52
1950004S11059   -18.3   52.4
1950004S11059   -20     54
1950004S11059   -22.1   55.9
1950004S11059   -26.2   59.8
1950012S14150   -14     146.9
1950012S14150   -14.4   145.8
1950012S14150   -14.9   145.4
1950012S14150   -15.8   145.6
1950012S14150   -18.9   149.1
1950012S14150   -22.3   152.5
1950013S14139   -16     139
1950013S14139   -16.3   139

简单地说,对于每个唯一的Serial_Num,我想要坐标。我期待类似的东西:

1950004S11059: {"GPS": (-11.1 , 59.1) , (-11.6, 57.8) , (-12.4, 56), ..., (-26.2, 59.8)}

然后我可以遍历每个GPS的{​​{1}}坐标并绘制。

我有一些我在其他地方使用的脚本,但主要依赖于.csv数据用于设置字典,Serial_Num为关键字。

但是,csv中的数据是顺序的,序列很重要。

为每个Serial_Num输出坐标列表的顺序是什么?按照它们在CSV中的顺序?

编辑:我现在正在看Pandas,因为它有Serial_Num方法可能会有所帮助。

2 个答案:

答案 0 :(得分:2)

<强>鉴于

名为fileprivate struct DateWrapper: Decodable { var date: Date private enum TimeCodingKeys: String, CodingKey { case datetime } init(from decoder: Decoder) throws { let dateString: String if let timeContainer = try? decoder.container(keyedBy: TimeCodingKeys.self) { dateString = try timeContainer.decode(String.self, forKey: .datetime) } else { let container = try decoder.singleValueContainer() if let string = try? container.decode(String.self) { dateString = string } else { date = try container.decode(Date.self) return } } if let date = Utils.date(from: dateString) { self.date = date } else if let date = Utils.date(from: dateString, with: "yyyy-MM-dd") { self.date = date } else { let context = DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Date format was not parseable.") throw DecodingError.dataCorrupted(context) } } } extension KeyedDecodingContainer { func decode(_ type: Date.Type, forKey key: K) throws -> Date { return try self.decode(DateWrapper.self, forKey: key).date } func decode(_ type: [Date].Type, forKey key: K) throws -> [Date] { var container = try nestedUnkeyedContainer(forKey: key) var dates: [Date] = [] while !container.isAtEnd { dates.append(try container.decode(Date.self)) } return dates } } extension UnkeyedDecodingContainer { mutating func decode(_ type: Date.Type) throws -> Date { return try self.decode(DateWrapper.self).date } } 的文件:

foo.csv

一些代码将数据解析为(序列,坐标)的元组:

Serial_Num     Latitude Longitude
1950004S11059   -11.1   59.1
1950004S11059   -11.6   57.8
1950004S11059   -12.4   56
1950004S11059   -13.2   54.6
1950004S11059   -13.8   53.8
1950004S11059   -14.8   52.7
1950004S11059   -15.9   52
1950004S11059   -18.3   52.4
1950004S11059   -20     54
1950004S11059   -22.1   55.9
1950004S11059   -26.2   59.8
1950012S14150   -14     146.9
1950012S14150   -14.4   145.8
1950012S14150   -14.9   145.4
1950012S14150   -15.8   145.6
1950012S14150   -18.9   149.1
1950012S14150   -22.3   152.5
1950013S14139   -16     139
1950013S14139   -16.3   139

<强>代码

我们构建了defaultdicts的嵌套:

import csv
import collections as ct


def read_file(fname):
    with open(fname) as f:
        reader = csv.reader(f)
        next(reader)
        for line in reader:
            #line = [x for x in line[0].split(" ") if x]
            yield line[0], tuple(map(float, line[1:]))

输出

data = ct.defaultdict(dict)
for serial, coords in (read_file("foo.csv")):
    if serial not in data:
        dd = ct.defaultdict(list)
    dd["GPS"].append(coords)
    data[serial] = dd

dict(data)

答案 1 :(得分:2)

这是一种方式。下面每个步骤的细分。

import pandas as pd

df = pd.read_csv('file.csv', delim_whitespace=True)
df['GPS'] = list(zip(df.Latitude, df.Longitude))
df.groupby('Serial_Num')['GPS'].apply(list).to_dict()

阅读数据

df = pd.read_csv('file.csv', delim_whitespace=True)

#        Serial_Num  Latitude  Longitude
# 0   1950004S11059     -11.1       59.1
# 1   1950004S11059     -11.6       57.8
# 2   1950004S11059     -12.4       56.0
# 3   1950004S11059     -13.2       54.6
# 4   1950004S11059     -13.8       53.8
# 5   1950004S11059     -14.8       52.7

制作元组列

df['GPS'] = list(zip(df.Latitude, df.Longitude))

#        Serial_Num  Latitude  Longitude             GPS
# 0   1950004S11059     -11.1       59.1   (-11.1, 59.1)
# 1   1950004S11059     -11.6       57.8   (-11.6, 57.8)
# 2   1950004S11059     -12.4       56.0   (-12.4, 56.0)
# 3   1950004S11059     -13.2       54.6   (-13.2, 54.6)
# 4   1950004S11059     -13.8       53.8   (-13.8, 53.8)
# 5   1950004S11059     -14.8       52.7   (-14.8, 52.7)

创建字典

df.groupby('Serial_Num')['GPS'].apply(list).to_dict()

# {'1950004S11059': [(-11.1, 59.100000000000001),
#                    (-11.6, 57.799999999999997),
#                    (-12.4, 56.0),
#                    (-13.199999999999999, 54.600000000000001),
#                    (-13.800000000000001, 53.799999999999997),
#                    (-14.800000000000001, 52.700000000000003),
#                    (-15.9, 52.0),
#                    (-18.300000000000001, 52.399999999999999),
#                    (-20.0, 54.0),
#                    (-22.100000000000001, 55.899999999999999),
#                    (-26.199999999999999, 59.799999999999997)],
#  '1950012S14150': [(-14.0, 146.90000000000001),
#                    (-14.4, 145.80000000000001),
#                    (-14.9, 145.40000000000001),
#                    (-15.800000000000001, 145.59999999999999),
#                    (-18.899999999999999, 149.09999999999999),
#                    (-22.300000000000001, 152.5)],
#  '1950013S14139': [(-16.0, 139.0), (-16.300000000000001, 139.0)]}
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