A South African editor's 'education'; Asking for Trouble: The Autobiography of a Banned Journalist, by Donald Woods. New York: Atheneum. $12.95.

Donald Woods and Steve Biko were two comets in South Africa's troubled political sky in the closing months of 1977. They were friends -- Mr. Woods a white liberal newspaper editor and Mr. Biko founder of the Black Consciousness Movement. Today Mr. Woods lives in exile in Britain; Mr. Biko died in South African police custody before the turmoil of 1977 was over. (His death has been attributed to a head injury sustained during interrogation by security police, but no official blame has been placed for the incident.)

Now, four years later, the question might be asked: Has either man left his mark on South Africa or earned a place in his country's history?

This writer would hazard the opinion that together both men will come to be identified with the last moment in the South African race tragedy when dialogue between blacks and whites migh have been possible to avoid the ever-growing threat of all-out race war.

Steve Biko believed in a multiracial South Africa where whites would be needed after blacks had one day eventually taken over. He did not advocate or preach violence, but, like Martin Luther King Jr. in the United States in the 1960s, he believed in the value of confrontation. (This reviewer makes these assertions so categorically on the basis of a long conversation with Mr. Biko on a chill evening on the outskirts of Kim William's Town only a week or so before the arrest that led to his demise a month later.)

What white authority in South Africa could not tolerate was Mr. Biko's quite remarkable influence on black urban youth: He could fire them to hold their heads high, to refuse to be cowed, and to be willing in the last resort to risk all for a South Africa one day run by blacks. This was something new, and history is bound to associate it with Steve Biko. Black South Africans of a generation yet to come will almost certainly canonize him as a martyr in the cause of black nationalism.

Donald Woods had cme by the 1970s -- albeit not easily or speedily -- to see that the best hope for the future of white South Africans was to enter into dialogue with the country's Steve Bikos. By them Mr. Woods was editor of the East London Daily Dispatch and was already a center of controversy as being "dangerously" liberal -- yet not at first to the extent of being able to accept the Black Consciousness Movement. He had, nevertheless, come a long way from the day 20 years earlier when he had told a law lecturer at the University of Cape Town: "[Blacks] should all be sent back to the reserves, where they belong. They're happier there. It's no good educating them and bringing them to the towns. It's either send them back to the reserves or shoot them -- it's them or us."

This autobiography is in large part the story of Mr. Woods's education, in the broadest sense, from his boyhood days as the son of a trading post owner until he decided he could no longer function in South Africa's stifling racial atmposphere. It is also the story of South Africa itself, moving over the past half century into the role of Africa's biggest industrial power and simultaneously into the defensive redoubt of Afrikaner nationalism, which its Afrikaans-speaking community has chosen to make it. (Afrikaners call the shots in South Africa. They outnumber English speakers 3 to 1 and have an absolute monopoly on political power.)

To this reader it was jotling to be reminded how far and how fast South Africa has come over the past 50 years. Bomvanaland of only half a century ago -- where Mr. Woods spent his boyhood -- often sounds in his record like the American frontier of the Midwest 150 years ago.

"Asking for Trouble" reads easily -- as it should, coming from the typewriter of such an experienced, lively, brave, freewheeling, and human newspaper editor as Donald Woods. The reservation of this reviewer is that Mr. Woods is inclined to quote overfrequently the direct speech of others, even when it is lade with crudities. To his credit, however, he does not overexploit his connection with Steve Biko; the authobiography is a balanced one.

Particularly fascinating is his account of his face-to-face encounters with former Prime Minister B. J. Vorster and of his "deals" with Piet Koornhof, minister in the present Cabinet responsible for relations with blacks, over lessening racial segregation in sports. The latter admitted quite frankly that his concessions were intended to buy time rather than as steps toward outright abolition of segregation.

Also interesting is Mr. Woods's detailed account of his final escape from South Africa across the border into Losotho, after the government's banning order had at last silenced and isolated him. It was a journey through the night with its scary moments. But there was no dramatic final swim to freedom across a dangerously swollen Telle River, as put out at the time. Mr. Woods was, in fact, driven across a bridge into Losotho by a friendly black Losotho post inspector who had picked him up at the border -- Mr. Woods, in clerical disguise , posing as a Roman Catholic priest late for a mass he had to celebrate on the Losotho side of the frontier. Mr. Woods explains that the "mythical" version was encouraged at the time as a smokescreen for those who had helped him.

Having said all this, there remains the question of Mr. Woods place in history. Probably no niche awaits him comparable to that awaiting Steve Biko. For one thing, Mr. Woods is an English-speaking South African, and -- harshly oversimplified though it may be to put it this way -- the role of the English-speaking community in the future of South Africa is probably irrelevant. The eventual showdown -- still a long way off -- will be between black nationalism and Afrikaner nationalism. Afrikaner nationalism made its choice when it silinced Steve Biko. And black nationalism shows every sign now of rejecting dialogue and moving toward sabotage and terrorism.