forked from GoesToEleven/GolangTraining
/
main.go
98 lines (83 loc) · 1.73 KB
/
main.go
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package main
import (
"encoding/csv"
"fmt"
"io"
"log"
"os"
"strconv"
)
type state struct {
id int
name string
abbreviation string
censusRegionName string
}
func parseState(columns map[string]int, record []string) (*state, error) {
id, err := strconv.Atoi(record[columns["id"]])
name := record[columns["name"]]
abbreviation := record[columns["abbreviation"]]
censusRegionName := record[columns["census_region_name"]]
if err != nil {
return nil, err
}
return &state{
id: id,
name: name,
abbreviation: abbreviation,
censusRegionName: censusRegionName,
}, nil
}
func main() {
// #1 open a file
f, err := os.Open("../state_table.csv")
if err != nil {
log.Fatalln(err)
}
defer f.Close()
// #2 parse a csv file
csvReader := csv.NewReader(f)
columns := make(map[string]int)
stateLookup := map[string]*state{}
for rowCount := 0; ; rowCount++ {
record, err := csvReader.Read()
if err == io.EOF {
break
} else if err != nil {
log.Fatalln(err)
}
if rowCount == 0 {
for idx, column := range record {
columns[column] = idx
}
} else {
// #3 do stuff for each row
state, err := parseState(columns, record)
if err != nil {
log.Fatalln(err)
}
// #4 add each row to stateLookup map
stateLookup[state.abbreviation] = state
}
}
// #5 lookup the state
if len(os.Args) < 2 {
log.Fatalln("expected state abbreviation")
}
abbreviation := os.Args[1]
state, ok := stateLookup[abbreviation]
if !ok {
log.Fatalln("invalid state abbreviation")
}
fmt.Println(state)
}
/*
at terminal:
go install
at terminal:
programName <state abbreviation>
for example:
step05_state-lookup CA
will show this:
&{5 California CA West}
*/