example_test.go

Documentation: encoding/csv

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package csv_test
     6  
     7  import (
     8  	"encoding/csv"
     9  	"fmt"
    10  	"io"
    11  	"log"
    12  	"os"
    13  	"strings"
    14  )
    15  
    16  func ExampleReader() {
    17  	in := `first_name,last_name,username
    18  "Rob","Pike",rob
    19  Ken,Thompson,ken
    20  "Robert","Griesemer","gri"
    21  `
    22  	r := csv.NewReader(strings.NewReader(in))
    23  
    24  	for {
    25  		record, err := r.Read()
    26  		if err == io.EOF {
    27  			break
    28  		}
    29  		if err != nil {
    30  			log.Fatal(err)
    31  		}
    32  
    33  		fmt.Println(record)
    34  	}
    35  	// Output:
    36  	// [first_name last_name username]
    37  	// [Rob Pike rob]
    38  	// [Ken Thompson ken]
    39  	// [Robert Griesemer gri]
    40  }
    41  
    42  // This example shows how csv.Reader can be configured to handle other
    43  // types of CSV files.
    44  func ExampleReader_options() {
    45  	in := `first_name;last_name;username
    46  "Rob";"Pike";rob
    47  # lines beginning with a # character are ignored
    48  Ken;Thompson;ken
    49  "Robert";"Griesemer";"gri"
    50  `
    51  	r := csv.NewReader(strings.NewReader(in))
    52  	r.Comma = ';'
    53  	r.Comment = '#'
    54  
    55  	records, err := r.ReadAll()
    56  	if err != nil {
    57  		log.Fatal(err)
    58  	}
    59  
    60  	fmt.Print(records)
    61  	// Output:
    62  	// [[first_name last_name username] [Rob Pike rob] [Ken Thompson ken] [Robert Griesemer gri]]
    63  }
    64  
    65  func ExampleReader_ReadAll() {
    66  	in := `first_name,last_name,username
    67  "Rob","Pike",rob
    68  Ken,Thompson,ken
    69  "Robert","Griesemer","gri"
    70  `
    71  	r := csv.NewReader(strings.NewReader(in))
    72  
    73  	records, err := r.ReadAll()
    74  	if err != nil {
    75  		log.Fatal(err)
    76  	}
    77  
    78  	fmt.Print(records)
    79  	// Output:
    80  	// [[first_name last_name username] [Rob Pike rob] [Ken Thompson ken] [Robert Griesemer gri]]
    81  }
    82  
    83  func ExampleWriter() {
    84  	records := [][]string{
    85  		{"first_name", "last_name", "username"},
    86  		{"Rob", "Pike", "rob"},
    87  		{"Ken", "Thompson", "ken"},
    88  		{"Robert", "Griesemer", "gri"},
    89  	}
    90  
    91  	w := csv.NewWriter(os.Stdout)
    92  
    93  	for _, record := range records {
    94  		if err := w.Write(record); err != nil {
    95  			log.Fatalln("error writing record to csv:", err)
    96  		}
    97  	}
    98  
    99  	// Write any buffered data to the underlying writer (standard output).
   100  	w.Flush()
   101  
   102  	if err := w.Error(); err != nil {
   103  		log.Fatal(err)
   104  	}
   105  	// Output:
   106  	// first_name,last_name,username
   107  	// Rob,Pike,rob
   108  	// Ken,Thompson,ken
   109  	// Robert,Griesemer,gri
   110  }
   111  
   112  func ExampleWriter_WriteAll() {
   113  	records := [][]string{
   114  		{"first_name", "last_name", "username"},
   115  		{"Rob", "Pike", "rob"},
   116  		{"Ken", "Thompson", "ken"},
   117  		{"Robert", "Griesemer", "gri"},
   118  	}
   119  
   120  	w := csv.NewWriter(os.Stdout)
   121  	w.WriteAll(records) // calls Flush internally
   122  
   123  	if err := w.Error(); err != nil {
   124  		log.Fatalln("error writing csv:", err)
   125  	}
   126  	// Output:
   127  	// first_name,last_name,username
   128  	// Rob,Pike,rob
   129  	// Ken,Thompson,ken
   130  	// Robert,Griesemer,gri
   131  }
   132
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