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| 1 | +// |
| 2 | +// datatools.go is a package for working with various types of data (e.g. CSV, XLSX, JSON) in support |
| 3 | +// of the utilities included in the datatools.go package. |
| 4 | +// |
| 5 | +// Copyright (c) 2017, Caltech |
| 6 | +// All rights not granted herein are expressly reserved by Caltech. |
| 7 | +// |
| 8 | +// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: |
| 9 | +// |
| 10 | +// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. |
| 11 | +// |
| 12 | +// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. |
| 13 | +// |
| 14 | +// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. |
| 15 | +// |
| 16 | +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 17 | +// |
| 18 | +package datatools |
| 19 | + |
| 20 | +import ( |
| 21 | + "encoding/csv" |
| 22 | + "fmt" |
| 23 | + "io" |
| 24 | + "math/rand" |
| 25 | + "time" |
| 26 | +) |
| 27 | + |
| 28 | +func selectedRow(rowNo int, record []string, rowNos []int) []string { |
| 29 | + if len(rowNos) == 0 { |
| 30 | + return record |
| 31 | + } |
| 32 | + for _, i := range rowNos { |
| 33 | + if i == rowNo { |
| 34 | + return record |
| 35 | + } |
| 36 | + } |
| 37 | + return nil |
| 38 | +} |
| 39 | + |
| 40 | +func shuffleRows(rows [][]string, src rand.Source) { |
| 41 | + // Create our random number source |
| 42 | + rn := rand.New(src) |
| 43 | + for a := len(rows) - 1; a > 0; a-- { |
| 44 | + // Pick a random element to swap with |
| 45 | + b := rn.Intn(a + 1) |
| 46 | + // Swap with a random element |
| 47 | + rows[a], rows[b] = rows[b], rows[a] |
| 48 | + } |
| 49 | +} |
| 50 | + |
| 51 | +// CSVRandomRows reads a in, creates a csv Reader and Writer and randomly selectes the rowCount |
| 52 | +// number of rows to write out. If showHeader is true it is excluded from the random row selection |
| 53 | +// and will be written to out before the randomized rows. |
| 54 | +// rowCount is the number of rows to return independent of the header row. |
| 55 | +func CSVRandomRows(in io.Reader, out io.Writer, showHeader bool, rowCount int, delimiter string) error { |
| 56 | + var err error |
| 57 | + |
| 58 | + headerRow := []string{} |
| 59 | + rows := [][]string{} |
| 60 | + r := csv.NewReader(in) |
| 61 | + w := csv.NewWriter(out) |
| 62 | + if delimiter != "" { |
| 63 | + r.Comma = NormalizeDelimiterRune(delimiter) |
| 64 | + w.Comma = NormalizeDelimiterRune(delimiter) |
| 65 | + } |
| 66 | + |
| 67 | + // read in our rows. |
| 68 | + for i := 0; err != io.EOF; i++ { |
| 69 | + rec, err := r.Read() |
| 70 | + if err == io.EOF { |
| 71 | + break |
| 72 | + } |
| 73 | + if err != nil { |
| 74 | + return fmt.Errorf("%s (%T %+v)", err, rec, rec) |
| 75 | + } |
| 76 | + if i == 0 && showHeader { |
| 77 | + headerRow = rec |
| 78 | + } else { |
| 79 | + rows = append(rows, rec) |
| 80 | + } |
| 81 | + } |
| 82 | + if showHeader && len(headerRow) > 0 { |
| 83 | + if err := w.Write(headerRow); err != nil { |
| 84 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, headerRow, headerRow) |
| 85 | + } |
| 86 | + } |
| 87 | + |
| 88 | + // Shuffle the rows, then write out the desired number of rows. |
| 89 | + rSrc := rand.NewSource(time.Now().UnixNano()) |
| 90 | + shuffleRows(rows, rSrc) |
| 91 | + |
| 92 | + // Now render the rowCount of the suffled rows |
| 93 | + if rowCount > len(rows) { |
| 94 | + rowCount = len(rows) |
| 95 | + } |
| 96 | + for i := 0; i < rowCount; i++ { |
| 97 | + row := rows[i] |
| 98 | + if row != nil { |
| 99 | + if err := w.Write(row); err != nil { |
| 100 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, row, row) |
| 101 | + } |
| 102 | + } |
| 103 | + } |
| 104 | + w.Flush() |
| 105 | + err = w.Error() |
| 106 | + if err != nil { |
| 107 | + return fmt.Errorf("%s\n", err) |
| 108 | + } |
| 109 | + return nil |
| 110 | +} |
| 111 | + |
| 112 | +// CSVRows renders the rows numbers in rowNos using the delimiter to out |
| 113 | +func CSVRows(in io.Reader, out io.Writer, showHeader bool, rowNos []int, delimiter string) error { |
| 114 | + var err error |
| 115 | + |
| 116 | + r := csv.NewReader(in) |
| 117 | + w := csv.NewWriter(out) |
| 118 | + if delimiter != "" { |
| 119 | + r.Comma = NormalizeDelimiterRune(delimiter) |
| 120 | + w.Comma = NormalizeDelimiterRune(delimiter) |
| 121 | + } |
| 122 | + for i := 0; err != io.EOF; i++ { |
| 123 | + rec, err := r.Read() |
| 124 | + if err == io.EOF { |
| 125 | + break |
| 126 | + } |
| 127 | + if err != nil { |
| 128 | + return fmt.Errorf("%s (%T %+v)", err, rec, rec) |
| 129 | + } |
| 130 | + if i == 0 && showHeader { |
| 131 | + if err = w.Write(rec); err != nil { |
| 132 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, rec, rec) |
| 133 | + } |
| 134 | + } else { |
| 135 | + row := selectedRow(i, rec, rowNos) |
| 136 | + if row != nil { |
| 137 | + if err = w.Write(row); err != nil { |
| 138 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, row, row) |
| 139 | + } |
| 140 | + } |
| 141 | + } |
| 142 | + } |
| 143 | + w.Flush() |
| 144 | + err = w.Error() |
| 145 | + if err != nil { |
| 146 | + return fmt.Errorf("%s\n", err) |
| 147 | + } |
| 148 | + return nil |
| 149 | +} |
| 150 | + |
| 151 | +// CSVRowsAll renders the all rows in rowNos using the delimiter to out |
| 152 | +func CSVRowsAll(in io.Reader, out io.Writer, showHeader bool, delimiter string) error { |
| 153 | + var err error |
| 154 | + |
| 155 | + r := csv.NewReader(in) |
| 156 | + w := csv.NewWriter(out) |
| 157 | + if delimiter != "" { |
| 158 | + r.Comma = NormalizeDelimiterRune(delimiter) |
| 159 | + w.Comma = NormalizeDelimiterRune(delimiter) |
| 160 | + } |
| 161 | + for i := 0; err != io.EOF; i++ { |
| 162 | + row, err := r.Read() |
| 163 | + if err == io.EOF { |
| 164 | + break |
| 165 | + } |
| 166 | + if err != nil { |
| 167 | + return fmt.Errorf("%s (%T %+v)", err, row, row) |
| 168 | + } |
| 169 | + if i == 0 && showHeader { |
| 170 | + if err = w.Write(row); err != nil { |
| 171 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, row, row) |
| 172 | + } |
| 173 | + continue |
| 174 | + } else if i > 0 { |
| 175 | + if err = w.Write(row); err != nil { |
| 176 | + return fmt.Errorf("Error writing record to csv: %s (Row %T %+v)", err, row, row) |
| 177 | + } |
| 178 | + } |
| 179 | + } |
| 180 | + w.Flush() |
| 181 | + err = w.Error() |
| 182 | + if err != nil { |
| 183 | + return fmt.Errorf("%s\n", err) |
| 184 | + } |
| 185 | + return nil |
| 186 | +} |
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